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THE  INFLUENCE  OF  BODILY 

POSTURE  ON  MENTAL 

ACTIVITIES 


ELMER  ELLSWORTH  JONES,  PH.D. 

Professor  of  Psychology  and  Education  in  the  State  Female  Normal 
School,  Farmville,  Va. 


ARCHIVES   OF  PSYCHOLOGY 

EDITED  BT  R.  S.  WOODWOKTH 


NO.    6,    OCTOBER,    19O7 


Columbia  Contributions  to  Philosophy  and  Psychology,  Vol.  XVI, 
No.   2 


NEW  YORK 
THE    SCIENCE    PRESS 


CONTENTS 


PAGE. 

CHAPTER        I.     INTRODUCTION 5 

CHAPTER      II.     LITERATURE 7 

CHAPTER  III.  LETTERS  FROM  WELL-KNOWN  INDIVIDUALS  STATING  THEIR 
FAVORITE  POSITION  OF  THE  BODY  FOR  THE  BEST  INTEL- 
LECTUAL WORK 16 

CHAPTER     IV.     DISCRIMINATION  OF  PITCH 21 

CHAPTER       V.     TACTILE  DISCRIMINATION 28 

CHAPTER     VI.     A  COMPARISON  OF  ADDING  ABILITY  IN  THE  HORIZONTAL  AND 

VERTICAL  POSITIONS  OF  THE  BODY 31 

CHAPTER  VII.  A  COMPARISON  OF  PULSE  RATE,  BLOOD  PRESSURE,  AND 
VISUAL  MEMORY  IN  THE  HORIZONTAL  AND  VERTICAL 

POSITIONS  OF  THE  BODY 38 

CHAPTER  VIII.  A  COMPARISON  OF  PULSE  RATE,  BLOOD  PRESSURE,  AND 
AUDITORY  MEMORY  IN  THE  HORIZONTAL  AND  VERTICAL 

POSITIONS  OF  THE  BODY 44 

CHAPTER     IX.     A  COMPARISON  OF  TAPPING  RAPIDITY  IN  THE  HORIZONTAL 

AND  VERTICAL  POSITIONS  OF  THE  BODY 48 

CHAPTER  X.  A  COMPARISON  OF  FATIGUE  IN  THE  HORIZONTAL  AND 
VERTICAL  POSITIONS  OF  THE  BODY — BY  THE  USE  OF 

THE  FINGER  DYNAMOMETER 51 

CHAPTER  XI.  A  COMPARISON  OF  THE  STRENGTH  OF  GRIP,  BY  THE  USE  OF 
THE  HAND  DYNAMOMETER,  IN  THE  HORIZONTAL  AND 

VERTICAL  POSITIONS  OF  THE  BODY 53 

CHAPTER   XII.     SOME  ADDITIONAL  DATA  ON  THE  PRECEDING  RESULTS 55 


CHAPTER  I 

INTRODUCTION 

A  thorough  consideration  of  the  circulation  of  the  blood  in  its  rela- 
tion to  mental  states  reveals  the  fact  that  slight  disturbances  in  the 
functioning  of  the  circulatory  organs  may  quite  seriously  affect  con- 
sciousness. Blood  in  the  brain  of  the  requisite  purity  and  rapidity  of 
flow  seems  quite  essential  to  normal  consciousness.  The  lack  of  proper 
stimulation  by  a  sufficient  quantity  of  oxygenated  blood  will  produce 
mental  stupidity  and  coma.  Any  derangement  of  the  functions  of 
those  organs  of  the  body  which  in  any  way  aid  in  contributing  pure 
blood  to  the  brain,  may  be  said  indirectly  to  affect  mental  states.  All 
modern  writers  upon  hygiene  insist  that  for  students  to  do  the  best 
work  in  school,  pure  air  and  plenty  of  exercise  are  essential,  not  only 
for  health,  but  for  efficiency  in  thinking.  Seats  and  desks  must  be 
comfortable,  and  of  the  proper  shape  and  height  to  keep  the  body  in  a 
position  suitable  for  normal  circulation  of  the  blood  and  breathing.  If 
either  are  impaired,  the  attentive  powers  are  distracted  and  mental 
conditions  become  less  efficient. 

Since  this  treatise  deals  with  a  comparison  of  mental  activity  in  the 
horizontal  and  vertical  positions  of  the  body,  and  mental  activities 
seem  so  dependent  upon  proper  blood  supply  to  the  brain,  it  becomes 
evident  that  the  problem  must  be  considered  very  largely  in  its  phys- 
iological bearings.  If  it  can  be  shown  that  in  these  two  positions  of 
the  body  there  are  marked  physiological  differences — differences  of 
blood  supply  to  the  brain;  differences  in  heart  action,  both  as  to 
rapidity  and  force;  differences  in  the  breathing  reflexes;  differences 
in  the  condition  of  the  musculature;  differences  hi  abdominal  pressure; 
and  differences  in  the  vaso-motor  activity  for  the  proper  distribution 
of  blood  to  the  various  parts  of  the  body — then  we  are  led  to  a  considera- 
tion of  the  present  problem,  whether  there  are  differences  in  mental 
activities  also. 

The  problem  has  been  attacked  previously  hi  no  thoroughly  system- 
atic manner.  The  chapter  on  the  literature  will  indicate  that  the 
physiological  phases  of  bodily  posture  have  been  studied,  but  no  system- 
atic work  has  been  done  upon  the  psychological  differences,  and  there 
is  little  indication  that  the  physiological  differences  even  suggest  a 
comparative  psychological  examination.  The  present  research  includes 
an  experimental  study  of  mental  processes  in  the  horizontal  and  vertical 
positions  only,  but  the  results  here  attained  seem  to  indicate  a  fruitful 
field  of  research  in  other  directions.  For  example,  it  would  be  interest- 
ing to  know  whether  walking  or  sitting  is  more  conducive  to  good 
thinking,  and  what  individual  differences  would  be  found.  Many 


6  INFLUENCE  OF  BODILY  POSTURE 

individuals  state  that  they  can  think  better  while  walking,  but  this 
could  be  tested  under  laboratory  conditions.  Then  there  are  indica- 
tions that  one  falls  into  habitual  postures  through  a  sort  of  selective 
process,  gradually  finding  the  one  in  which  he  feels  that  he  can  do  the 
best  mental  work.  It  would  be  interesting  to  test  such  individuals 
and  determine  whether  such  positions  are  really  conducive  to  better 
thought,  or  whether  in  some  other  position  they  will  not  do  equally 
well. 

It  will  be  noted  in  the  experimental  chapters  that  individuals  vary 
considerably  in  all  the  tests  made.  However,  the  results  in  most  in- 
stances seem  to  conform  to  those  we  would  normally  expect  from  a 
theoretical  consideration  of  physiological  conditions.  Yet  this  is  not 
always  the  case. 

For  the  most  part,  the  literature  of  the  subject  will  be  discussed 
in  Chapter  II,  though  occasionally  it  may  be  necessary  to  make  reference 
to  other  investigators  in  the  succeeding  chapters.  The  methods  and 
apparatus  employed  in  the  experimental  work  will  be  discussed  usually 
in  the  chapter  in  which  the  tests  and  results  are  recorded. 


CHAPTER  II 

LITERATURE 

The  psychology  of  bodily  position  has  been  little  studied  experimen- 
tally. There  is  no  doubt  that  many  writers  have  considered,  as  of 
some  significance,  the  fact  that  individuals  vary  in  bodily  posture  in 
executing  many  of  the  ordinary  tasks;  but  the  trouble  has  not  been 
undertaken  to  subject  individuals  to  accurate  tests  and  find  out 
whether  there  is  a  favorable  position  for  certain  types  of  mental  life  or 
not.  Introspective  evidence  is  not  lacking  that  certain  bodily  postures 
are  favorable  for  particular  mental  tasks,  but  psychologists  are  skep- 
tical as  to  the  validity  of  the  mere  introspective  evidence  without  corrob- 
orative testimony  from  the  experimental  laboratory.  Consequently, 
the  great  portion  of  the  literature  will  bear  rather  upon  the  physiological 
aspects  of  the  question  than  the  psychological. 

Lauder-Brunton1  discusses  at  some  length  the  effect  which  gravity  has 
upon  the  diaphragmatic  action,  and  the  outward  pressure  upon  the 
abdominal  wall.  In  the  upright  posture,  the  diaphragm  moves  ver- 
tically, but  the  abdominal  walls  and  intestines  move  in  a  horizontal 
plane.  Consequently,  in  this  position  there  is  no  lifting  work  for  the 
diaphragm  to  do.  When  a  man  is  lying  on  his  back,  however,  the  case 
is  quite  different.  During  inspiration,  the  diaphragm  encroaches  upon 
the  intestines,  and  has  actually  to  exert  enough  force  to  raise  them 
and  also  the  abdominal  walls.  Thus  the  recumbent  posture  may  be  of 
advantage  in  diseases  in  which  the  weight  of  the  intestines  will  drive 
the  diaphragm  back  up  into  the  thorax  and  aid  expiration.  In 
heart  and  lung  diseases,2  however,  the  opposite  seems  to  be  the  case. 
Most  patients  have  a  desire  to  sit  up  in  bed,  or  even  to  walk  about 
slowly.  Leonard  Hill  points  out  in  a  rather  significant  way,  also, 
that  it  is  possible  to  give  an  accurate  diagnosis  of  many  diseases  by 
studying  the  posture  of  the  patient.  Even  mental  diseases  of  the 
various  types  have  their  peculiar  bodily  postures.  Also  in  perfectly 
normal  individuals,  psychic  states  more  or  less  influence  the  bodily 
posture,  while  weather  conditions,3  temperature,  humidity,  wind, 
etc.,  have  not  only  been  shown  to  effect  the  posture,  but  also  to  have 
striking  causal  relations  to  very  significant  acts  of  will.  Lauder- 
Brunton  also  points  out  that  the  varying  types  of  emotion  have  their 
individually  characteristic  bodily  postures,  and  this  posture  seems  to  be 


1  Lauder-Brunton,  Popular  Science  Monthly,  42,  33. 

2  Leonard  Hill,  Cerebral  Circulation,  London,  1896,  p.  78. 

3  Dexter,  "Conduct  and    the  Weather,"  Psychological  Re-view,  Monograph 
Supplement,  No.  10,  1899. 


8  INFLUENCE  OF  BODILY  POSTURE 

a  real  expression  of  the  emotion.  James1  illustrates  the  same  point 
by  saying:  "Whistling  to  keep  up  courage  is  no  mere  figure  of  speech. 
On  the  other  hand,  sit  all  day  in  a  moping  posture,  sigh,  and  reply  to 
everything  with  a  dismal  voice,  and  your  melancholy  lingers.  There 
is  no  more  valuable  precept  in  moral  education  than  this,  as  all  who 
have  experience  know:  if  we  wish  to  conquer  undesirable  emotional 
tendencies  in  ourselves,  we  must  assiduously,  and,  in  the  first  instance, 
cold-bloodedly,  go  through  the  outward  movements  of  those  contrary 
dispositions  which  we  prefer  to  cultivate." 

Again  Lauder-Brunton  shows  in  a  remarkable  passage  how  bodily 
posture  seems  to  have  great  influence  upon  the  free  play  of  ideas.  "An 
•experience  of  my  own  once  showed  me  how  dependent  the  brain  is  upon 
the  supply  of  blood.  I  was  called  upon  one  night,  after  a  long  day's 
work,  to  write  an  article  immediately.  I  sat  down  with  pen,  and  ink, 
and  paper,  but  not  a  single  idea  came  into  my  head,  not  a  single  word 
could  I  write.  Lying  back,  I  soliloquized:  'the  brain  is  the  same  as  it 
was  yesterday,  and  it  worked  then :  why  will  it  not  work  today?'  Then 
it  occurred  to  me  that  I  was  not  so  tired  the  day  before,  and  probably 
the  circulation  was  a  little  brisker  than  to-day.  I  next  thought  of  the 
various  experiments  on  the  connection  between  the  cerebral  circulation 
and  mental  activity,  and  I  concluded  that  if  the  blood  would  not  come 
to  the  brain,  the  best  thing  would  be  to  bring  the  brain  down  to  the 
blood.  I  laid  my  head  flat  upon  the  table,  and  at  once  my  ideas  began 
to  flow,  and  my  pen  began  to  run  across  the  paper.  I  thought,  'I  am 
getting  on  so  well  now  I  may  sit  up,'  but  the  moment  I  raised  my  head, 
the  mind  became  an  utter  blank ;  so  I  put  my  head  down  again  flat  upon 
the  table  and  finished  my  article  in  that  position." 

In  President  Baker's2  address  before  the  Anthropological  Section 
of  the  American  Association  for  the  Advancement  of  Science,  in  1890, 
he  calls  attention  to  the  remarkable  changes  that  have  taken  place 
in  the  human  body  as  it  gradually,  through  the  long  processes  of 
evolution,  assumed  the  upright  position.  Since  gravity  must  play  a 
very  important  part  in  the  visceral  and  circulatory  organs,  therefore 
any  change  in  the  equilibrium  must  necessarily  cause  some  disturbance 
in  organic  functions.  These  disturbances  will  necessarily  weaken  the 
animal  and  will  interfere  with  its  assuming  the  upright  posture.  There 
is  of  necessity,  then,  a  long  period  of  struggle,  both  mental  and  physical 
in  which  the  organic  structures  of  the  body  are  gradually  adapting 
themselves  to  the  new  position.  There  is  much  evidence  that  this 
struggle  is  still  going  on,  and  that  the  adaptation  is  still  far  from  com- 
plete. He  enters  into  a  rather  extensive  description  of  various  organs 
which  have  been  modified,  and  are  still  being  modified,  in  order  to 

1  James,  Principles  of  Psychology,  Vol.  II.,  p.  463. 

1  Frank  Baker,  The  Ascent  of  Man,  Amer.  Asso.  for  the  Adv.  of  Sc.,  1890. 


LITERATURE  9 

become  perfectly  adapted  to  a  vertical  posture.  The  pelvis,  which 
forms  the  support  for  the  internal  organs,  has  become  more  disc-like 
and  thicker  and  the  opening  through  it  has  become  much  smaller. 
These  changes  are  more  pronounced  hi  the  female  than  hi  the  male, 
since  it  must  bear  the  weight  of  the  pregnant  uterus.  Indeed  it  has 
become  a  sort  of  compromise  between  an  arrangement  of  great  strength 
for  support,  and  ease  in  child  delivery.  Since  the  head  of  the  child 
was  greatly  increased  with  the  vertical  posture,  childbirth  became 
much  more  difficult,  and  the  struggle  has  been  terrific.  Woman's 
entire  physique  shows  signs  of  very  many  physical  changes,  and  in  no 
animal  is  there  such  a  difference  in  the  sexes  as  in  man  and  woman. 
Hernia  is  another  sign  of  imperfect  adaptation.  In  quadrupeds  the 
weight  of  the  abdominal  organs  is  swung  from  the  spine  by  the  tunica 
abdominalis.  In  man  this  has  entirely  disappeared  except  hi  the 
groin,  and  here  it  frequently  gives  way,  causing  rupture.  Uterine 
displacements  are  almost  unknown  in  the  horizontal  posture,  but  are 
among  the  most  common  sexual  complaints  of  the  vertical  female. 
The  "knee  and  elbow"  treatment  of  this  malady,  which  is  decidedly 
quadrupedal  in  nature,  is  suggestive  of  the  imperfect  adjustment  to 
the  vertical  posture.  Stone1  in  the  bladder  is  unknown  to  quadru- 
pedal animals  because  all  sediment  is  easily  drained  off  through  the 
urethra.  President  Baker  quotes  from  Dr.  Erasmus  Darwin  as  follows: 
"  It  has  been  supposed  by  some  that  all  mankind  were  formerly  quadru- 
peds as  well  as  hermaphrodites,  and  that  some  parts  of  the  body  are 
not  yet  so  convenient  to  an  erect  posture  as  to  a  horizontal  one.  As 
the  fundus  of  the  bladder  in  an  erect  posture  is  not  exactly  over  the 
insertion  of  the  urethra,  whence  it  is  seldom  completely  evacuated, 
and  thus  renders  mankind  more  subject  to  the  stone  than  if  he  had 
preserved  his  horizontally."  The  appendix  is  a  vestigial  organ  and 
only  functioned  far  down  the  biological  scale  below  man.  In  quadru- 
peds it  is  so  placed  that  gravity  aids  in  freeing  it  from  foecal  accumula- 
tions, and  it  is  thus  seldom  diseased.  The  liver,  in  quadrupeds,  hangs 
from  the  spine,  but  in  man  it  depends  from  the  diaphragm,  which  in 
turn  has  attachments  with  the  fibrous  coverings  of  the  heart,  and  these 
hi  turn  are  continuous  with  the  fascia  of  the  neck,  so  that  in  reality, 
the  liver  hangs  suspended  from  the  upper  thorax.  This  decreases 
the  degree  of  action  of  the  diaphragm,  confines  the  lungs  more  closely, 
and  must  interfere  somewhat  with  the  action  of  the  blood,  and  con- 
sequently impairs  the  vertical  animal's  power  to  endure  rapid  muscular 
exercise.  There  are  also  many  difficulties  in  the  circulation  of  the 
blood  in  the  vertical  animal,  such  as  the  raising  of  the  blood  through 
the  ascending  vena-cava,  whence  comes  congestion  of  the  liver,  and 
cardiac  dropsy.  Then  in  the  descending  vena-cava  there  is  a  tendency 

1  Dr.  Erasmus  Darwin,  Temple  of  Nature,  Canto  II.  (Note),  Jan.  i,  1802. 


10  INFLUENCE  OF  BODILY  POSTURE 

for  the  blood  to  drop  too  rapidly,  producing  syncope.  Valves  of  the 
circulatory  system  are  arranged  for  the  horizontal  position  of  the  body, 
and  not  the  vertical.  They  are  wholly  lacking  in  some  of  the  more 
important  of  the  vertical  trunks,  yet  are  found  in  many  of  the  hori- 
zontal veins  where  they  are  not  at  all  needed. 

Probably  the  most  careful  student  of  the  physiological  effects  of 
bodily  posture  is  Leonard  Hill,1  the  great  English  physiologist. 
In  his  chapter  in  Schafer's  "Text-Book  of  Physiology,"  he  compares  the 
whole  circulatory  system  to  a  network  of  distensible  tubes,  having 
a  pump  in  the  midst  of  the  system  to  force  the  blood  in  both  directions — 
upward  against  gravity  and  downward  with  gravity.  By  the  valves 
in  the  veins,  the  tonicity  of  the  arterioles,  and  the  muscles  of  the 
abdominal  walls,  the  circulation  is  supposedly  efficient  with  the  body 
in  any  position,  save  the  head  down.  This  is  not  actually  true,  as  will 
be  shown  in  some  of  the  experimental  chapters,  for  many  individuals 
are  not  endowed  with  the  vaso-motor  mechanism  which  renders  the 
compensation  for  gravity  perfect.  However,  with  a  perfectly  normal 
individual,  the  mechanism  is  adequate,  and  the  circulation  will  be  effi- 
cient with  the  body  in  any  of  the  various  positions  ordinarily  assumed. 

Leonard  Hill2  shows  that  the  great  splanchnic  area  forms  a  sort 
of  resistance  box  of  the  circulation.  If  the  vessels  here  are  contracted, 
the  blood  must  make  its  way  to  the  muscles  and  brain  and  other  parts 
of  the  body.  If  these  vessels  are  dilated,  the  blood  lodges  there,  and 
he  claims  that  they  are  capacious  enough  when  fully  distended  to  hold 
all  the  blood  of  the  body.  He  affixed  a  dog  to  a  board  which  could  be 
swung  around  an  axis,  throwing  the  animal  alternately  in  the  hori- 
zontal and  vertical  feet-down  positions,  and  then  by  opening  the 
jugular  and  carotid  artery  and  cannulae  connected  with  manometers, 
he  was  able  to  read  the  arterial  and  venous  pressure  in  the  two  positions 
of  the  body.  Dropping  the  animal  into  the  vertical  feet-down  posture, 
the  arterial  pressure  falls  to  a  slight  extent,  and  then  rises  to  the 
normal  level.  The  hydrostatic  effect  is  here  practically  nihil  because 
of  the  integrity  of  both  the  vaso-motor  center  and  the  respiratory 
pump.  By  cutting  the  splanchnic  nerves,  the  arterial  pressure  falls 
very  low  in  the  vertical  feet-down  posture,  which  shows  that  gravity 
becomes  of  vital  importance  when  the  vaso-motor  tone  of  the  splanch- 
nic area  is  destroyed.  If,  in  addition,  the  respiratory  pump  is 
thrown  out  of  gear,  the  circulation  becomes  impossible. 

This  same  writer3  has  shown  that  a  rise  in  the  arterial  pressure 
produces  an  increased  velocity  of  blood  in  the  brain.  In  great  rises  of 


1  Leonard  Hill,  "  Effect  of  Change  of  Posture  on  Circulation,"  Schafer's  Text- 
Book  of  Physiology,  Vol.  II,  p.  90. 

*  Leonard  Hill,  British  Medical  Journal,  1897,  Vol.  i,  p.  959. 
1  Leonard  Hill,  Cerebral  Circulation,  London,  1896,  p.  78. 


LITERATURE  11 

pressure  by  absinthe,  he  shows  that  the  outflow  of  blood  from  the 
torcular  increased  from  twice  to  six  times.  And  the  metabolism  of  the 
brain  was  found  to  be  very  little  as  compared  to  that  of  the  muscles. 
The  practice  of  wearing  belts  for  weakness  and  after  parturition  has 
a  real  physiological  significance,  since  it  increases  the  output  of  blood 
and  the  pressure  of  same  in  the  brain.  In  this  connection,  he  refers 
to  the  significant  fact  that  some  people  lose  their  memory1  in  the 
vertical  posture  and  regain  it  upon  recumbency.  Also  some  individuals 
do  better  mental  work  when  in  the  horizontal  position.  The  Rabe- 
laisian effects  of  fear,  manifested  by  soldiers  before  battles,  may  be 
due  to  the  splanchnic  dilation  of  the  blood  vessels  and  the  blood  rushing 
to  the  abdomen.  Every  stimulus  that  affects  the  nervous  system 
affects  the  vaso-motor  centers,  and  thus  has  an  effect  upon  the  cerebral 
circulation.  A  pleasant  emotion  raises  the  blood  pressure,  and  an 
unpleasant  one  lowers  it.  The  vaso-motor  is  a  sort  of  protective 
arrangement  whereby  blood  can  be  drawn  from  the  abdomen  to  supply 
the  brain.  When  a  certain  stimulus  demands  cerebral  response,  the 
splanchnic  area  constricts,  and  blood  is  driven  rapidly  through  the 
brain.  With  this  mechanism  slightly  out  of  order,  change  in  the 
posture  would  produce  differences  in  blood  supply  to  the  brain,  and 
we  would  thus  expect  to  find  slight  differences  in  mental  states. 

The  experiments  of  Erlanger  and  Hooker2  agree  very  closely  with 
those  of  Hill,  and  show  that  the  changes  in  the  circulation  of  the  blood, 
due  to  changes  hi  posture  are  very  largely  hydrostatic,  and  in  the 
majority  of  cases  not  at  all  due  to  the  inefficency  of  the  vaso-motor 
mechanism.  They  show  by  the  use  of  the  von  Kries  tachygraph  that 
the  acceleration  of  blood  flow  per  heart-beat  is  greatest  in  the  recum- 
bent posture  and  smallest  in  the  vertical  posture.  These  results, 
together  with  those  of  Hill,  would  suggest  a  possible  theory  for  greater 
intellectuality  hi  the  recumbent  posture.  Their  research  shows  also 
that  posture  has  a  marked  effect  on  the  character  of  the  urine,  chlo- 
rides, phosphates,  and  nitrogen  being  much  smaller  in  the  standing 
than  in  the  recumbent  posture. 

Kiesow3  has  investigated  the  blood  pressure  of  a  large  number  of 
individuals,  and  has  found  that  the  position  of  the  body  is  a  very  im- 
portant factor.  In  eighty  per  cent,  of  the  subjects,  the  pressure  is 
greatest  in  the  vertical  posture  and  least  in  the  recumbent  posture. 
Violent  gymnastic  exercise  increases  the  pressure  from  70  or  80  to  100 
or  110.  Massage  increases  the  pressure. from  60  to  90.  The  pressure 
keeps  up  for  about  fifteen  minutes  and  then  returns  to  the  normal. 
Coffee  will  increase  the  blood  pressure  from  10  to  15  points,  which 

1  Leonard  Hill,  Cerebral  Circulation,  London,  1896,  p.  112. 

2  Erlanger  and  Hooker,  Amer.  Jour,  of  Physiology,  Vol.  X,  1903-4. 

3  Kiesow,  Arch.  Ital.  de  Biol.,  Vol.  XXIII,  p.  198,  1895. 


12  INFLUENCE  OF  BODILY  POSTURE 

continues  for  about  an  hour.  In  his  series  of  experiments  to  determine 
whether  intellectual  effort  and  sustained  attention  produced  changes 
in  the  blood  pressure,  he  reaches  the  conclusion  that  it  is  only  when 
they  verge  into  feelings  and  psychic  disturbances  of  some  sort  that  we 
can  detect  changes  in  blood  pressure  as  a  result.  Of  course  if  deep 
psychosis  produces  change  in  blood  pressure,  we  might  infer  that  the 
reverse  would  also  be  true,  and  if  posture  has  influence  in  the  change 
of  blood  pressure  and  rapidity  of  flow,  it  would  indirectly  affect  the 
mental  life. 

One  of  the  most  exhaustive  treatises  on  blood  pressure  is  that  of 
Janeway, "  Clinical  Study  of  Blood  Pressure,"  1904.  He  brings  together 
a  great  deal  of  the  clinical  evidence  from  numerous  sources  upon  the 
subject,  and  throws  some  light  upon  the  present  problem.  He  shows 
that  blood  pressure  depends  upon  four  separate  and  distinct  things, 
viz.,  the  energy  of  the  heart,  the  peripheral  resistance,  the  elasticity 
of  the  arterial  walls,  and  the  volume  of  the  circulating  fluid.  Hill  and 
others  would  add  to  these,  the  bodily  posture.  The  nerves1  which 
have  greatest  effect  on  the  general  blood  pressure  are  those  which  are 
distributed  to  the  splanchnic  region.  So  long  as  these  nerves  are  in- 
tact, splanchnic  circulation  can  usually  compensate  for  the  most  ex- 
treme narrowing  of  the  rest  of  the  arterial  tree,  but  if  a  section  is  made 
through  them  the  arterial  pressure  immediately  falls.  Bezold,2  in  his 
researches  in  Leipzig,  reached  similar  conclusions.  If,  also,  the  vaso- 
motor  centers  themselves  are  impaired  in  their  activity,  the  pressure 
falls  when  the  body  is  changed  from  the  horizontal  to  the  vertical 
posture. 

Janeway3  shows  that  the  volume  of  blood  in  the  body  is  small 
when  compared  with  the  full  capacity  of  the  veins,  arteries,  and 
capillaries.  Some  of  the  vessels  are  nearly  empty  a  good  portion  of 
the  time,  and  distribution  in  the  necessary  parts  is  effected  by  the 
tonus  of  the  muscles  in  the  walls  of  the  vessels.  If  the  cord  is  de- 
stroyed, the  blood  all  flows  quickly  into  the  veins  and  the  animal  bleeds 
to  death  inwardly.  An  amount  of  fluid4  greater  than  the  total  blood 
volume  of  the  body  has  been  infused  into  the  veins  and  blood-vessels, 
without  raising  the  pressure  above  a  point  frequently  reached  in 
normal  life.  Pawlow,  quoted  by  Janeway  on  p.  26,  put  immense 
quantities  of  bouillon  into  the  blood  vessels  of  a  dog  without  any  rise 
in  the  pressure.  These  experiments  show  that  pressure  does  not  de- 

1  Ludwig  und  Cyon,  Bericht  d'.  Sack.  Gesellsch.  d.  Wissensch.  Math.  Phys.  Cl. 
1866. 

1  Bezold,  Untersuchungen  uber  die  Innervation  d.  Herzens,  pp.  223-229,  1863. 

s  Janeway,  Clinical  Study  of  Blood  Pressure,  p.  25,  1904. 

4  Worm-Mullerm,  Bericht  d.  Sach.  Gesellsch  d.  Wissensch.  Math.  Phys.  Cl., 
1873,  PP-  573-664. 


LITERATURE  13 

pend  so  much  upon  the  quantity  of  blood  in  the  vessels,  but  upon  the 
position  of  the  body  and  the  mechanism  for  changing  the  calibre  of  the 
vessels  to  drive  the  blood  to  the  part  of  the  body  where  it  is  needed. 

Keith,1  in  the  Lancet  for  March,  1903,  discusses  the  "Nature  and 
Anatomy  of  Enteroptosis,"  and  indirectly  throws  some  little  light  on 
the  importance  of  posture  and  the  effects  of  gravity  upon  some  of  the 
vital  organs.  The  writer  endeavors  to  show  that  enteroptosis  is  a 
disease  which  is  brought  about  by  a  lack,  on  the  part  of  the  muscles 
of  the  abdominal  wall,  to  resist  the  effects  of  gravity  upon  the  organs 
of  the  thorax  and  abdominal  region.  It  is  a  condition  found  only  in 
animals  of  the  upright  posture,  and  most  frequently  in  man.  He  says 
that  the  thoracic  and  abdominal  organs  are  poised  between  the  muscles 
of  inspiration  and  expiration.  This  poise  between  the  two  cavities  for 
most  individuals  remains  about  constant  throughout  life.  Some- 
times, however,  the  muscles  of  inspiration  get  the  upper  hand,  and  the 
viscera  of  the  thorax  and  abdomen  become  displaced,  resulting  in  what 
is  called  enteroptosis.  It  may  affect  particularly  any  one  organ,  or  it 
may  affect  a  whole  group,  bearing  strongly  down  into  the  abdomen,  the 
stomach,  liver,  spleen,  and  intestines.  Post-mortem  examinations 
show  that  these  organs  vary  as  much  as  two  or  three  inches  from  the 
normal  position,  causing  intense  pain  and  completely  changing  the 
mental  and  physical  life  of  the  individual. 

There  is  likewise  an  affection,  known  as  Glenard's2  disease,  usually 
met  with  in  women,  due  to  repeated  pregnancies,  or  undue  exertion 
or  injuries.  It  is  a  general  falling  of  the  abdominal  organs  due  to 
gravity.  The  transverse  colon  is  the  first  to  descend,  and  then  the 
stomach  is  drawn  down  so  that  the  pylorus  is  greatly  compressed  and 
does  not  allow  the  food  to  pass  freely.  The  whole  mass  of  the  small 
intestines  becomes  prolapsed  and  the  abdomen  becomes  distended.  Liver 
and  kidneys  become  loose  and  are  described  as  floating.  The  patient 
suffers  greatly  and  can  only  be  relieved  by  assuming  the  horizontal 
position  or  wearing  tight  bandages  around  the  abdomen.  This  disease 
has  a  great  effect  on  the  mental  life  also,  in  many  instances  producing 
moroseness  and  melancholy.  Such  results  would  be  expected  from  so 
great  a  displacement  of  the  vital  organs. 

Kornfeld3  found  that  in  practically  all  kinds  of  physical  exercise, 
with  the  body  in  various  positions,  the  blood  pressure  rises  above  the 
normal  at  first,  and  then  there  is  a  sudden  falling  off.  Within  one 
minute  after  the  ceasing  of  the  exercise,  the  pressure  is  again  normal. 
He  found  also  that  exercises  which  required  great  attention  made  the 
pressure  go  higher.  A  melody  on  a  violin,  when  the  subject  was  trying 

1  Keith,  "The  Nature  and  Anatomy  of  Enteroptosis,"  Lancet,  March,  1903. 

2  Treves,  "  Treatment  of  Glenard's  Disease,  "Brit.  Med.  Journal,  Vol.  i,  1896. 

3  Kornfeld,  Wein.  Med.  Blot.,  Vol.  XXII,  1899. 


14  INFLUENCE  OF  BODILY  POSTURE 

to  recognize  it,  caused  the  blood  pressure  to  rise  from  110  mm.  to 
150  mm.,  but  as  soon  as  the  melody  was  recognized  the  pressure  fell  to 
130  mm.  This  experiment  shows,  possibly  as  well  as  any  on  record, 
that  mental  states  are  in  some  intimate  manner  associated  with  blood 
pressure  to  the  brain.  If  so,  then  posture,  which  has  been  shown  to 
have  great  influence  on  blood  pressure,  will  also  have  some  effect  on 
one's  mental  life. 

It  has  been  shown1  that  upon  the  child  assuming  the  upright 
posture,  several  changes  in  the  spine  take  place  in  order  to  counteract 
the  effects  of  gravity.  At  first  a  sharp  forward  curve  develops  in  the 
lower  lumbar  region,  continued  up  into  the  dorsum.  The  back  thus 
becomes  hollowed.  Gradually  a  compensating  curve  develops  in  the 
dorsal  region,  forming  a  well  marked  backward  curve.  Then  a  third 
develops  later  in  the  cervical  region  which  is  more  closely  akin  to  the 
lumbar.  During  the  greater  part  of  the  time  that  these  curves  are 
forming,  the  child  is  in  school.  An  examination  of  the  boys  of  the 
Montreal  High  School  reveals  the  fact  that  23  per  cent,  of  them  had 
lowered  shoulders,  and  30  per  cent,  the  "gorilla  type"  of  posture  when 
standing.  About  14  per  cent,  of  all  college  students  examined  at  Mc- 
Gill  University  have  similar  deformities.  It  cannot  be  safely  asserted 
without  actual  testing  that  these  deformities  bring  about  correlative 
mental  defects,  but  since  they  are  spinal  defects,  we  would  expect 
from  them  some  derangement  of  the  mental  life.  The  posture  of 
children  in  school,  while  sitting  and  standing,  should  be  wavched  very 
carefully,  and  any  incipient  defects  carefully  corrected.  Posture  is 
not  only  important  from  the  standpoint  of  the  child's  health  and 
activity,  but  because  it  furnishes  us  indications  of  habitual  modes  of 
thought  in  children.  A  thorough  study  of  the  posture  of  children 
would  reveal  many  means  of  building  up  the  physical  health.  Howe2 
says  that  in  standing  rather  than  sitting  we  see  the  habitual  modes  of 
thought  of  the  student  finding  expression.  The  erect  head  is  the 
expression  of  self-confidence  and  conscious  power.  The  drooping  head 
and  the  sunken  chest  is  the  expression  of  weakness. 

One  of  the  best  contributions  to  the  study  of  posture  in  its  rela- 
tions to  blood  pressure  and  heart-beat  is  that  by  Crampton,3  Assistant 
Superintendent  of  Physical  Training  in  the  New  York  City  Schools. 
By  means  of  a  table  correlating  heart-beat  and  blood  pressure  in  the 
horizontal  and  vertical  positions  of  the  body,  he  determines  physical 
condition.  The  index  to  physical  condition  he  asserts  to  be  the 

1  McKenzie,  "  Influence  of  School  Life  on  the  Curvature  of  the  Spine,"  N.  E. 
A.  Report,  p.  939,  1898. 

1  Rowe,  Physical  Nature  of  the  Child,  Chapter  X. 

3  Crampton,  "A  Test  of  Condition:  Preliminary  Report,"  Medical  News,  Sept., 
1905. 


LITERATURE  15 

efficiency  of  the  vaso-motor  mechanism  in  controlling  the  blood  sup- 
ply to  the  splanchnic  area.  This  is  shown  by  the  table,  and  individuals 
are  divided  into  nine  groups  according  to  the  changes  in  heart-beat 
and  blood  pressure  when  elevated  from  the  horizontal  to  the  vertical 
position.  I  shall  refer  to  this  table  again  in  my  experimental  work 
where  I  have  attempted  to  correlate  mental  efficiency  with  physical 
condition  according  to  his  standards. 

N.  Vaschide,1  in  1904,  made  a  series  of  experiments  in  tactile 
perception  by  the  use  of  the  aesthesiometers  under  standard  conditions 
on  consecutive  days.  His  subjects  were  naked  so  as  to  be  free  from 
all  pressure  of  the  clothing.  Then  the  same  experiments  were  repeated 
with  conditions  such  as  to  necessitate  marked  circulatory  modifications. 
Bands  were  tied  about  the  arms  and  neck  and  limbs  so  as  to  bring  about 
congestion  hi  certain  parts.  The  position  of  the  body  was  varied  con- 
siderably also  to  produce  congestion  and  free  circulation.  His  results 
are  as  follows:  Tactile  sensibility  varies  under  the  influence  of  change 
of  position  and  freedom  of  the  circulation.  Fineness  of  discrimination 
depends  immediately  upon  the  efficiency  and  strength  of  circulation. 
By  a  mere  shift  of  the  bodily  position  so  as  to  bring  about  a  different 
condition  of  circulation,  measurable  differences  of  sensation  are  pro- 
voked. He  emphasizes  the  fact  that  a  powerful  and  constant  flow  of 
blood  increases  the  sensibility.  Anemia  produces  a  diminution  of 
sensation  qualities,  as  does  also  congestion  of  blood.  Nervous  diseases 
and  supersensitiveness  are  frequently  due  to  blood  pressure  in  certain 
parts  of  the  body.  Any  member  spontaneously  flooded  with  blood 
becomes  more  sensitive.  Vaschide  insists  that  all  tactile  senses  need 
revision  according  to  these  principles. 

All  the  literature  upon  the  subject  of  blood  pressure  and  distribu- 
tion of  blood  to  all  parts  of  the  body,  indicates  clearly  that  bodily 
posture  has  a  very  potent  influence  in  determining  the  same.  And 
since  consciousness  depends  for  its  normal  state  upon  the  proper 
circulation  of  the  blood  to  the  brain,  we  are  justified  in  assuming  that 
in  all  individuals,  posture  alone  will  produce  measurable  variations 
in  the  various  senses,  and  even  in  the  deeper  processes,  such  as  memory, 
judgment,  and  reasoning.  The  experimental  part  of  this  dissertation 
will  undertake  to  measure  these  variations  as  found  by  changing  the 
bodily  posture  of  the  subject,  and  at  the  same  time  measuring  the 
variability  in  the  psychic  processes. 

1  Vaschide,  "Les  rapports  de  la  circulation  sanguine  et  la  mesure  de  la  sen- 
sibilite  tactile,"  C.  R.  Acad.  D.  Sci.,  Vol.  139,  pp.  486-488,  1904. 


CHAPTER  III 

LETTERS    FROM    WELL-KNOWN    INDIVIDUALS    STATING    THEIR   FAVORITE 
POSITION  OF  THE  BODY  FOR  THE  BEST  INTELLECTUAL  WORK 

In  the  beginning  of  this  research,  it  seemed  quite  essential  to  know 
whether  individuals  have  favorite  positions  and  attitudes  of  the  body 
in  which  they  habitually  do  their  intellectual  work,  and  also,  if 
possible,  to  find  out  how  these  came  to  be  assumed,  whether  by  mere 
chance,  or  whether,  by  gradual  experimentation  and  elimination  of  un- 
satisfactory postures,  a  fixed  one  was  assumed  in  which  the  best  work 
could  be  accomplished.  The  writer  was  convinced  from  observation 
of  studenls  in  classrooms  and  study  rooms,  and  from  the  postures  of 
children  in  the  kindergarten  and  lower  grades  of  the  public  schools, 
that  great  individual  differences  would  be  found.  It  was  apparent 
that  these  differences  were  not  mere  chance  variations,  but  seemed 
rather  to  be  due  to  a  process  of  selection  by  which  that  bodily  position 
is  gradually  assumed,  which  conduces  to  the  easiest  flow  of  ideas. 
In  order  to  investigate  these  various  points,  several  hundred  letters 
were  written  to  men  who  have  gained  eminence  in  at  least  fifteen 
different  walks  of  life.  A  personal  letter  was  written  to  each  individual, 
stating  the  purpose  of  the  research,  and  asking  a  few  questions  which 
could  be  easily  and  quickly  answered.  Some  three  hundred  and  fifty 
responses  came  as  a  result  of  this  inquiry,  which,  in  the  opinion  of  the 
writer,  give  rather  conclusive  evidence  that  mental  states  are  some- 
what dependent  upon  bodily  position,  and  that  most  individuals  who 
do  highly  specialized  intellectual  labor  find  that  there  is  some  one 
bodily  posture  which  will  very  greatly  facilitate  their  work. 

A  few  of  these  letters  are  given  here  to  show  certain  tendencies 
which  seem  to  prevail,  and  to  throw  some  light  on  the  prominent  part 
which  posture  does  seem  to  play  in  our  best  thinking. 

The  following  letter  is  from  a  man  who  has  for  years  been  prominent 
in  politics  in  the  West,  has  been  in  Congress,  and  was  twice  in  succes- 
sion governor  of  a  state. 

"Dear  Sir: — Your  letter  of  inquiry  concerning  the  position  of  my 
body  when  I  do  my  best  thinking,  interested  me,  for  I  have  often 
wondered  why  my  ideas  always  seem  clearer  after  I  go  to  bed  at  night. 
I  have  formed  the  habit  for  many  years  of  spending  an  hour  or  more 
doing  some  careful  thinking  immediately  after  I  retire.  If  I  am  to 
deliver  an  address,  I  think  out  my  speech  in  bed,  generally  just  the 
night  before.  You  ask  me  to  state  how  I  got  into  this  habit.  I  think 
it  dates  back  to  my  school  days  when  I  invariably  solved  my  difficult 
mathematical  problems  after  retiring.  Sometimes  when  I  arose  in  the 
morning,  I  had  forgotten  the  solution,  and  could  not  get  it  during  the 
day,  but  was  sure  to  work  it  out  the  next  night  again." 


LETTERS  FROM  WELL-KNOWN  INDIVIDUALS         17 

I  may  say  that  this  is  a  very  general  type  of  letter.  A  number  of 
individuals  refer  to  the  solution  of  problems  in  mathematics  as 
easier  in  the  horizontal  position  of  the  body,  and  say  that  they  fre- 
quently reserve  the  most  difficult  work  until  after  they  retire.  In- 
conversing  with  individuals,  the  writer  has  found  that  these  are  not 
isolated  cases  but  that  practically  everyone  has  some  special  position 
of  the  body  which  apparently  must  be  assumed  to  get  the  best  mental 
results,  and  it  is  surprising  how  many  have  referred  to  doing  the 
most  difficult  mental  tasks  in  bed. 

The  following  letter  was  received  from  a  journalist  in  the  Middle 
West,  whose  editorials  are  without  doubt  of  the  very  first  rank.  He 
is  also  a  man  of  great  political  influence,  and  a  first-class  orator. 

"My  Dear  Sir: — In  reply  to  your  inquiry,  will  say  that  I  can  do  my 
best  thinking  while  lying  down.  I  have  in  my  office  a  divan  upon 
which  I  recline  when  thinking  out  anything  particularly  difficult,  for 
I  have  found  that  ideas  come  more  easily,  and  are  more  easily  clothed 
in  appropriate  words  in  this  position." 

From  this  letter,  I  assume  that  the  writer  dictates  to  his  stenog- 
rapher, and  that  in  this  instance  we  have  illustrated  that  the  horizontal 
position  not  only  conduces  to  clear  thinking  and  clearer  ideas,  ideas 
that  better  fit  into  the  apperceptional  mass  of  the  editor,  but  also  that 
it  facilitates  the  physiological  expression  of  these  ideas  in  appropriate 
language. 

Another  letter  describes  a  posture  which  has  decidedly  physiological 
advantages  from  the  standpoint  of  the  circulation  of  the  blood.  It 
reads  as  follows: 

"Dear  Sir: — I  wonder  what  psychologists  will  investigate  next. 
Your  queries  cause  me  to  wonder  what  you  are  about.  The  posture 
that  I  assume  for  literary  work  will  amuse  you.  I  have  written  the 
greater  portion  of  all  my  books  while  lying  on  the  floor  on  my  belly." 

This  writer's  name  is  almost  a  household  word  in  America.  Few 
men  stand  higher  in  the  literary  world  to-day,  and  every  boy  has 
read  his  books  with  pleasure. 

The  position  which  this  writer  assumes  brings  the  pressure  of  the 
weight  of  the  body  upon  the  splanchnic  area  and  serves  to  keep  the 
blood  squeezed  from  the  capacious  veins  there,  and  distributed  to  other 
parts  of  the  body.  This  position1  would  not  only  favor  the  vaso- 
motor  mechanism  for  the  compensation  for  gravity,  but  would  permit 
of  no  congestion  of  this  region  whatever  and  keep  the  brain  stimulated 
with  blood.  These  effects  might  more  than  compensate  for  the  in- 
conveniences of  the  position  for  writing.  And  indeed,  chirography, 

1  Leonard  Hill,  "Experiments  on  Blood  Pressure,"  Brit.  Med.  Jour.,  1897, 
Vol.  I. 


18  INFLUENCE  OF  BODILY  POSTURE 

judging  from  the  manuscripts  themselves,  scarcely  enters  into  the 
consciousness  of  writers. 

Another  letter  from  an  American  psychologist  may  be  of  interest 
as  bearing  directly  upon  this  same  subject  of  the  position  of  the  body 
when  doing  mental  work. 

"Sir:  I  have  never  considered  the  position  of  the  body  in  mental 
work  as  of  very  much  importance;  however,  I  am  free  to  confess  that 
much  of  my  best  thinking  has  been  done  while  reclining.  It  is  my 
custom  in  my  study  to  think  out  many  problems  while  lying  on  a 
couch  on  my  right  side  with  my  right  elbow  under  my  head.  I  cannot 
give  you  the  genesis  of  this  position,  though  I  think  it  dates  back  into 
childhood." 

This  position  is  rather  peculiar,  save  that  it  is  practically  horizontal. 
No  other  individual  describes  this  exact  position.  It  might  be  ex- 
plained simply  as  the  most  convenient  one  in  his  particular  study. 
The  couch  may  be  so  placed  with  reference  to  his  study  table  that  it  is 
easy  to  fall  over  on  it  and  assume  a  horizontal  position  on  the  right 
side. 

From  the  evidence  in  the  letters  received,  there  is  another  type  of 
position  much  used  in  intellectual  work  which  may  be  designated 
as  semi-horizontal.  It  is  usually  described  as  "easy."  The  feet  are 
placed  upon  a  table  or  other  high  object,  the  chair  being  forced  back 
upon  the  two  hind  legs,  usually  leaning  against  the  wall  or  other 
support.  This  posture,  I  have  noted  many  times,  is  a  favorite  one 
with  students  in  dormitories,  and  in  their  own  private  rooms  every- 
where. Thirty-five  out  of  eighty-one  students  visited  in  Hartley 
Hall,  Columbia  University,  for  observation  of  the  position  in  which 
they  were  engaged  in  study,  were  found  to  have  their  feet  upon  a  table 
or  chair  or  some  other  object  which  elevated  them  very  much  and 
gave  the  body  what  might  be  called  a  semi-horizontal  position.  Morris 
chairs  are  a  special  device  invented  to  bring  about  this  particular 
position. 

The  following  letters  will  indicate  a  very  pronounced  tendency 
among  eminent  individuals  to  assume  this  position  in  doing  intel- 
lectual work. 

"Dear  Sir:  I  will  say  that  I  can  do  my  best  thinking  in  my  own 
quiet  study,  with  my  feet  thrown  loosely  up  over  the  corner  of  my  table, 
or  possibly  even  higher.  I  have  been  accustomed  to  this  position  for 
years,  and  even  write  so.  My  writing  is  done  chiefly  on  a  large  pine 
board  which  I  hold  across  my  lap." 

"Dear  Sir:  In  answer  to  your  inquiry  will  say  that  I  sometimes 
recline  on  a  couch  while  I  write,  but  more  frequently  sit  in  a  large,  low- 
bottomed  chair  with  my  feet  either  upon  another  chair,  or  upon  the 
table  in  front  of  me.  I  can  assign  no  special  reason  for  taking  this 
position  except  that  it  seems  perfectly  comfortable,  and  this  fact  alone 
seems  conducive  to  good  thinking." 


LETTERS  FROM  WELL-KNOWN  INDIVIDUALS         19 

"My  Dear  Sir:  The  greater  part  of  my  writing  has  been  done  in 
a  large  arm  chair  with  a  very  slanting  back.  Across  the  arms  I  usually 
place  a  large  board,  forming  a  sort  of  lean  back  table  right  in  front  of 
me.  My  feet  are  then  placed  high,  so  as  to  give  me  almost  a  reclining 
posture,  and  yet  a  most  convenient  position  for  writing." 

The  following  letter  is  from  a  man  of  national  reputation  as  a  writer 
of  negro  dialect.  In  addressing  him,  I  asked  him  if  there  was  any 
motor  tendency  on  his  part  to  assume  typical  negro  postures  while 
attempting  to  depict  minutely  certain  characters  and  types.  His 
answer  throws  a  little  light  on  this  interesting  question  in  addition 
to  the  one  before  us. 

"My  Dear  Sir:  In  reply  to  your  inquiry  concerning  my  bodily 
position  while  writing  my  negro  stories,  will  say  that  it  varies  some- 
what. In  the  summer  time,  I  write  a  great  deal  out  of  doors,  lying 
upon  the  lawn,  or  anywhere  I  can  have  an  opportunity  to  watch  one 
or  two  of  my  servants  work,  and  hear  their  conversation.  I  generally 
have  them  doing  odd  jobs  near  me  for  purposes  of  which  they  are  totally 
ignorant.  In  my  study,  I  usually  sit  in  a  low  chair  with  my  feet  high, 
and  some  means  of  writing  across  my  lap,  or  on  a  small  table  at  my 
side.  I  do  not  find  that  I  have  a  tendency  to  make  any  bodily  move- 
ments of  negroes  that  I  wish  to  describe  but  I  try  to  see  in  my  imagina- 
tion very  clearly  every  movement  and  attitude  described." 

Of  course  we  do  not  have  here  the  testimony  of  a  psychologist  as 
to  these  images.  It  may  be  that  if  instruments  for  recording  delicate 
movements  were  attached  to  this  writer,  it  would  be  found  that  the 
imagery  had  a  background  in  much  movement. 

One  other  letter  of  the  type  belonging  to  this  group  is  sufficient 
to  show  the  general  tendency  to  a  semi-horizontal  posture. 

"Dear  Sir:  I  can  do  my  best  thinking  in  a  Morris  chair  with  the 
back  at  a  low  angle  and  my  feet  on  a  high  stool.  This  position  has 
now  become  habitual  and  I  involuntarily  drop  into  it,  though  it  has 
been  learned  in  the  past  two  years.  I  find  it  the  most  comfortable 
and  the  most  conducive  to  an  easy  flow  of  ideas.  I  formerly  worked, 
sitting  at  my  study  table." 

About  sixty-five  per  cent,  of  all  letters  received  conform  pretty 
clearly  to  these  two  types.  This  investigation  seems  to  indicate  rather 
definitely  that  a  large  number  of  writers,  men  of  science,  ministers, 
statesmen,  and  those  who  have  become  distinguished  in  various  lines, 
chose  practically  the  horizontal  position  for  their  most  careful  intel- 
lectual work.  The  remainder  of  the  letters  is  difficult  to  classify. 
Quite  a  large  number  state  that  they  do  their  best  and  most  careful 
thinking  during  some  solitary  walk.  Many  say  that  they  must  get 
down  over  their  work  at  a  table,  and  seem  to  indicate  that  there  is 
some  efficacy  in  holding  the  head  up  with  one  hand  and  writing  with 
the  other.  One  says  that  he  must  have  the  temperature  of  his  room 
about  eighty  degrees,  and  must  sit  at  a  low  table.  Some  few  declare 


20  INFLUENCE  OF  BODILY  POSTURE 

that  the  position  makes  no  difference  in  their  mental  life  so  far  as  they 
can  see.  At  one  time  they  will  recline,  at  another  walk  about  their 
room,  and  at  another  quietly  sit  at  their  study  table.  Several  state 
that  some  sort  of  contact  of  the  hand  with  various  parts  of  the  face  or 
nose,  or  the  stroking  of  the  hair  seems  to  stimulate  mental  activity. 
This  is  nearly  always  mentioned  as  being  helpful  while  sitting  at  a 
table  engaged  in  study.  There  are  several  examples  of  individuals 
who  seem  to  arrive  at  their  most  original  ideas  while  in  bed,  and  arise 
to  write  them  down  and  clothe  them  in  proper  language.  On  the  other 
hand,  a  few  assert  that  a  pleasing  thought  can  be  put  into  the  best 
language  only  after  they  retire  at  night.  One  minister  states  that  he 
works  over  all  his  material  for  a  sermon  at  his  study  table,  but  puts 
it  into  the  proper  form  for  delivery  while  in  bed.  Another  does  just 
the  reverse.  A  poet  writes,  "No  man  ever  became  a  poet  sitting  at 
a  table;  he  must  lounge  and  dream."  There  are  vast  individual 
differences  in  this  remaining  thirty-five  per  cent.  No  two  seem  ex- 
actly to  agree  in  a  favorite  posture,  and  indeed  posture  does  not  seem 
to  influence  their  mentality  to  a  great  extent.  There  may  be  counteract- 
ing forces  in  their  temperament  which  overbalance  any  effect  which 
posture  might  have.  It  will  be  shown  later,  however,  in  the  experi- 
mental portion  of  this  work  that  posture  is  a  great  factor  determining 
efficiency  in  mental  states,  even  though  the  subject  is  not  aware  of  it, 
and  may  deny  it.  A  subject  may  declare  introspectively  that  a  certain 
position  is  preferable  for  certain  mental  tests,  and  yet  show  by  actual 
experiment  that  the  opposite  position  for  him  is  preferable.  This,  of 
course,  shows  that  there  is  little  validity  in  the  opinions  of  the  authors 
of  the  letters  previously  quoted,  and  that  such  testimony  can  have 
little  value  until  it  is  verified  by  careful  experimentation  under  labora- 
tory conditions. 


CHAPTER  IV 

DISCRIMINATION   OF   PITCH 

Method. — In  this  chapter  three  series  of  experiments  upon  the  dis- 
crimination of  pitch  will  be  described.  The  effort  is  to  determine 
whether  there  is  a  general  tendency  for  individuals  to  discriminate 
better  in  the  horizontal  or  vertical  position  of  the  body.  The  first 
series  of  tests  was  made  upon  school  children  of  the  eighth  grade  in  the 
public  schools,  ranging  hi  age  from  ten  to  thirteen  years.  A  cot  was 
provided  in  a  quiet  room,  upon  which  the  children  could  recline  for  the 
tests  in  the  horizontal  position.  For  the  vertical  they  were  simply 
required  to  stand  upright,  and  at  an  equal  distance  from,  and  the  same 
relative  position  to,  the  stimulus.  For  these  tests  a  mandolin  was  used, 
tuned  to  concert  pitch.  The  A  strings  were  made  to  vary  from  each 
other  from  two  to  four  vibrations  per  second,  according  to  the  threshold 
of  the  subject.  At  the  beginning  of  the  testing  of  each  subject,  enough 
preliminary  trials  were  made  to  determine  the  probable  threshold,  and 
then  this  difference  was  maintained  throughout  the  recorded  series  for 
this  subject.  The  A  strings  tuned  in  this  fashion  were  used  "open" 
for  all  subjects,  so  as  to  give  the  same  quality  of  tone.  Care  was  taken 
also  to  pick  the  strings  evenly  and  with  the  same  intensity,  and  at  the 
same  distance  from  the  bridge  in  all  experiments.  The  instrument 
used  was  a  Tony  Beahl  make,  having  an  excellent  quality  of  tone, 
and  easily  dampened  by  the  fingers,  without  giving  any  unpleasant 
over-tones  or  vibrations  which  would  distract  the  attention.  The 
method  used,  as  in  all  the  tests  on  the  discrimination  of  pitch,  was  that 
of  right  and  wrong  cases.  One  hundred  tests  in  each  position  were 
made  upon  all  subjects  with  the  exception  of  two,  who  were  given  one 
hundred  and  fifty.  The  two  A  strings,  tuned  as  previously  explained, 
were  picked,  an  interval  of  two  seconds  intervening,  and  the  subject 
was  asked  to  say  whether  the  second  was  higher  or  lower.  If  unable  to 
decide,  he  was  asked  to  guess.  The  probable  error  was  then  deter- 
mined from  the  percentage  of  the  right  cases  by  the  Fullerton  and 
Cattell1  table. 

In  all  the  experiments  on  discrimination  of  pitch  the  subjects  tended 
to  become  easily  fatigued.  In  consequence  it  was  necessary  to  change 
the  posture  of  the  subject  quite  frequently,  in  order  that  the  fatigue 
effects  should  be  distributed  equally  in  the  two  positions.  Generally 
ten  tests  were  made  in  one  position,  and  then  the  subject  was  changed 
to  the  other;  if,  however,  signs  of  fatigue  appeared  sooner,  the  subject 
was  alternated  from  one  position  to  the  other  every  five  experiments. 

1  Fullerton  and  Cattell,  On  the  Perception  of  Small  Differences,  p.  16,  1892. 


22 


INFLUENCE  OF  BODILY  POSTURE 


In  this  way  there  was  no  chance  for  the  constant  error  of  fatigue  to 
enter  more  strongly  in  one  position  than  another.  The  same  holds 
for  the  practice  effects,  which  were  undoubtedly  present  in  a  large 
number  of  subjects.  Similarly,  whatever  improvements  were  made 
by  the  individual  subjects,  will  be  found  equally  distributed  in  the 
two  positions,  because  of  the  frequent  change  of  posture. 

TABLE  I 

The  following  table  gives  the  results  of  tests  made  on  eleven  school  children 
for  the  discrimination  of  pitch. 


I 

oriz 

ontal 

Vertical 

Subject 

Sex 

^ 

Number 
ofexperi- 

inents 

Per 

cent 
right 

P.  E. 

A 

Number 
fexperi 
ments 

Per  cent 
right 

P.  E. 

Com- 
parative 
>er  cents 

G. 

Male 

3 

TOO 

6.S 

5-2 

3 

IOO 

69 

4.0 

77% 

A. 

Female 

4 

100 

82 

2.9 

4 

IOO 

88 

-3 

79% 

M. 

Male 

J 

100 

82 

2.2 

3 

IOO 

76 

.8 

127% 

S. 

Female 

3 

100 

9* 

1-5 

3 

IOO 

82 

.2 

146% 

H. 

Male 

4 

150 

79 

3-3 

4 

150 

84 

-7 

81% 

L. 

Male 

3 

100 

94 

i-3 

3 

IOO 

9^ 

•5 

115% 

M.G. 

Female 

3 

IOO 

75 

3-0 

3 

IOO 

82 

.2 

73% 

H.T. 

Female 

4 

100 

60 

10.6 

4 

IOO 

6? 

6.0 

57% 

B. 

Male 

3 

150 

79 

2-5 

3 

150 

74 

3-" 

124% 

G.  S. 

Male 

4 

IOO 

81 

3-o 

4 

IOO 

90 

2.  I 

7°% 

H. 

Female 

2 

IOO 

68 

2-9 

2 

IOO 

73 

2.2 

76% 

M. 

M. 

M. 

M. 

M. 

J?.v8 

to. 

79  .6 
M.V 

2.8 

M.V 

93% 
M.V. 

7.8 

1.6 

7-4 

.8 

25% 

Explanation  of  Table  I. — All  of  the  tables  in  discrimination  of 
pitch  are  somewhat  alike,  and  an  explanation  of  Table  I  will  clarify 
all.  The  results  to  the  left  of  the  middle  line  of  the  table  are  those 
gotten  for  the  horizontal  position,  and  those  to  the  right  of  the  line 
for  the  vertical.  Column  one  represents  the  subject,  column  two 
the  sex,  column  three  the  difference  of  vibration  per  second  of  the  two 
A  strings  of  the  mandolin,  column  four  the  actual  number  of  tests  made 
upon  the  individual  subject,  column  five  the  per  cent,  of  right  cases, 
column  six  the  probable  error,  determined  from  the  difference  in  vibra- 
tion per  second  and  the  per  cent,  of  right  cases.  The  last  column  on 
the  right  of  the  table  represents  the  per  cent,  which  the  probable 
error  in  the  vertical  position  is  of  that  in  the  horizontal. 

This  group  of  children  was  selected  from  a  large  grade,  and  repre- 
sents those  who  have  been  in  school  the  same  number  of  years  and 
who  have  had  the  same  teachers.  The  children,  therefore,  represent 
a  group  having  had  precisely  the  same  training  so  far  as  the  school 


DISCRIMINATION  OF  PITCH  23 

is  concerned,  yet  representing  rather  remarkable  individual  differences. 
The  probable  errors  in  the  horizontal  position  vary  from  1.3  to  10.6, 
though  the  latter  is  far  above  the  mean.  In  the  vertical  posture  they 
vary  from  1.5  to  6,  with  a  mean  of  2.8. 

It  does  not  appear  from  the  investigation  that  discrimination  of 
pitch  is  very  closely  correlated  with  musical  ability.  Subject  G  is 
decidedly  the  most  musical  of  the  whole  group,  while  subject  M  does 
not  know  the  difference  in  tunes.  A  comparison  of  the  probable 
errors  shows  that  M's  discrimination  of  pitch  is  more  than  twice  as 
good  as  G's.  The  subject  H.  T.,  who  does  by  far  the  poorest  of  the 
group  in  discrimination,  has  a  beautiful  voice  and  sings  quite  well, 
though  she  has  difficulty  in  keeping  on  the  key.  She  also  plays  the 
piano  well  for  one  of  her  age.  Subject  L,  who  has  the  best  record  for 
discrimination  of  pitch,  is  very  bright  in  all  lines,  but  takes  no  special 
interest  in  music,  and  does  not  sing  at  all.  On  the  other  hand,  subject 
S,  who  has  a  very  good  record  in  discrimination,  is  musical.  It  does 
not  appear,  however,  as  a  result  of  these  tests  that  the  two,  musical 
ability  and  discrimination  of  pitch,  are  correlated. 

It  will  be  observed,  too,  by  a  comparison  of  the  probable  errors  in 
the  two  positions  of  the  body,  that  there  seems  to  be,  for  this  group, 
an  advantage  in  the  vertical  posture,  for  the  discrimination  of  pitch. 
The  succeeding  tables  will  show  this  same  tendency  even  more  mark- 
edly. There  seems  to  be  no  physiological  reason  why  sound  waves 
should  affect  the  organs  of  hearing  differently  in  the  two  positions, 
and  the  fact  is  possibly  to  be  explained  on  the  basis  of  association  and 
habit.  Table  IV  shows  that  practice  by  those  subjects  who  could 
discriminate  much  better  in  the  horizontal  posture,  tends  to  reduce  the 
differences  of  discrimination  in  the  two  positions  of  the  body.  This 
explanation  should  be  further  borne  out  by  the  fact  that  in  adults, 
where  habit  and  association  are  more  deeply  rooted,  the  differences 
in  discrimination  in  the  two  positions  are  more  decidedly  marked.  The 
mean  comparative  per  cents,  of  the  probable  errors  for  the  children 
is  93,  and  for  the  adults  hi  Table  II,  it  is  71.  This  seems  too  great  a 
difference  to  be  explained  as  a  chance  variation. 

Explanation  of  Table  II. — The  method  for  obtaining  the  results  in 
Table  II  was  somewhat  similar  to  that  used  for  Table  I.  A  balancing 
table  was  used  for  changing  the  subjects  easily  and  quickly  from  one 
position  to  another,  built  somewhat  on  the  plan  of  Mosso's  instrument. 
The  subject  was  placed  upon  this  instrument  in  the  horizontal  position, 
and  given  ten  tests,  after  which  he  was  rotated  to  the  vertical  position 
and  given  more.  This  method  was  continued  until  one  hundred 
tests  in  each  position  were  made.  Instead  of  the  mandolin,  the  mono- 
chord  was  used  for  giving  the  stimuli.  Middle  C  was  the  tone  used  as 
the  standard,  and  the  other  string  made  to  vary  from  this  from  one 


24 


INFLUENCE  OF  BODILY  POSTURE 
TABLE  II 


This  table  is  a  summary  of  results  of  tests  for  discrimination  of  pitch  upon 
twelve  students  in  the  University  of  Leipzig,  by  the  use  of  the  monochord. 


Horizontal 

Vertical 

Subject 

Sex 

A 

Number 
of  experi- 
ments 

Percent 
right 

P.  B. 

A 

Number 
of  experi- 
ments 

Per 

cent 
right 

P.  E. 

Com- 
parative 
percenta 

G.  L. 

Male 

3 

100 

83 

2.  12 

3 

IOO 

92 

1.44 

66% 

E.  M. 

2 

100 

70 

2.56 

2 

IOO 

74 

2.  I 

82% 

C.  H. 

4 

100 

85 

2-59 

IOO 

81 

3  ° 

"7% 

M.  D. 

2 

IOO 

92 

•9 

IOO 

94 

.85 

94% 

L.  C. 

2 

IOO 

60 

5-26 

IOO 

82 

1-4 

27% 

C.  B. 

3 

IOO 

68 

4-34 

IOO 

74 

3-iS 

73% 

E.  M/ 

C.  W. 

2 

1  20 

IOO 

83 
70 

2.56 

1  20 

IOO 

89 
76 

•55 
19 

78% 
74% 

M.  A. 

4 

IOO 

82 

2.9 

4 

IOO 

9i 

2.O 

69% 

G.  S. 

2 

IOO 

78 

1.7 

2 

IOO 

86 

I  .2 

7i% 

M.S. 

3 

IOO 

69 

4-0 

3 

IOO 

77 

2-7 

67% 

L.  C. 

2 

IOO 

81 

1-5 

2 

IOO 

75 

2.0 

133% 

M. 

M. 

M. 

M. 

M. 

76.7 

2.5 

82.6 

1.8 

7'% 

M.V. 

M.V. 

M.V. 

M.V. 

M.V. 

7-9 

•  9 

6-5 

.8 

17% 

to  four  vibrations  per  second,  according  to  the  threshold  of  the  subject. 
The  threshold  was  roughly  determined  in  every  case  by  a  series  of 
preliminary  tests.  As  in  the  previous  tests,  the  method  of  right  and 
wrong  cases  was  employed. 

The  important  fact  shown  by  this  table  is  that  out  of  the  twelve 
subjects  tested,  ten  do  decidedly  better  in  the  vertical  posture.  The 
probable  errors,  which  are  correct  measures  of  their  discriminative 
ability,  are  a  little  over  1.4  times  as  large  in  the  horizontal  as  in  the 
vertical  posture  for  the  whole  group.  The  individual  differences  are 
important  in  this  group  also.  It  will  be  seen  that  the  probable  errors 
in  the  horizontal  position  vary  between  the  limits  .7  and  5.26,  when 
the  mean  is  2.5,  and  in  the  vertical  position  the  extremes  are  0.55 
and  3.15  with  a  mean  of  1.8.  These  differences  are  very  striking 
indeed.  The  subjects  were  mostly  students  engaged  in  the  study  of 
psychology,  and  some  of  them  had  taken  rather  extensive  laboratory 
courses. 

Explanation  of  Table  III. — The  method  employed  in  obtaining  the 
results  incorporated  in  this  table  was  similar  to  those  used  in  Tables 
I  and  II,  save  that  the  Koenig  tuning  forks  were  used  for  giving  the 
stimuli.  Two  forks  of  1024  vs.  each  were  used,  and  by  the  use  of  a 
rider  fastened  upon  one,  the  desired  differences  in  vibration  per  second 
between  the  two  forks  could  be  secured.  Great  care  was  used  in  count- 
ing the  beats  for  the  desired  difference.  Several  graduate  students  were 


DISCRIMINATION  OF  PITCH 
TABLE  III 


25 


This  table  gives  results  of  tests  for  discrimination   of  pitch   upon  nineteen 
students  of  Columbia  University,  by  the  use  of  Koenig  tuning  forks. 


Horizontal 

Vertical 

Number 

Per 

Number  of 

Per 

Compara- 

Subject 

Sex 

A 

of  experi- 
ments 

cent 
right 

P.  E. 

A 

experi- 
ments 

cent 
right 

P.  E. 

tive  per 
cents 

M. 

Male 

3 

IOO 

72 

3-4 

3 

IOO 

76 

2.8 

82% 

C. 

" 

IOO 

59 

5-8 

IOO 

65 

3-5 

60% 

G. 

u 

IOO 

82 

i-4 

IOO 

82 

i-7 

121% 

D. 

a 

IOO 

72 

2-3 

IOO 

71 

2-4 

104% 

J. 

" 

IOO 

78 

i-7 

IOO 

83 

i-4 

82% 

S.  G.  T. 

u 

IOO 

72 

2-3 

IOO 

78 

i-7 

7^^ 

L.  C.  S. 

u 

IOO 

72 

2-3 

IOO 

71 

2.4 

104% 

J.G. 

a 

150 

72 

2-3 

150 

77 

1.8 

78% 

E.  L.  M. 

u 

IOO 

68 

4-3 

IOO 

75 

3-0 

69% 

F.  M.  H. 

it 

IOO 

69 

i-3 

IOO 

65 

1-7 

130% 

S.  F. 

u 

IOO 

58 

6.6 

IOO 

7i 

2.4 

36% 

F.  L.  W. 

" 

IOO 

67 

i-5 

IOO 

78 

.88 

58% 

Prof.  W. 

a 

IOO 

68 

i-4 

IOO 

75 

i  .00 

71% 

S.  S. 

u 

IOO 

59 

2-9 

IOO 

64 

1.8 

62% 

W.  H.  S. 

u 

IOO 

72 

2-3 

IOO 

84 

i-3 

56% 

L.  F.  F. 

a 

IOO 

58 

6.6 

IOO 

66 

3-2 

48% 

G.  S. 

" 

IOO 

79 

1.6 

IOO 

88 

i  .  i 

68% 

S. 

Female 

3 

IOO 

74 

3-i 

3 

IOO 

68 

4-3 

138% 

B. 

a 

3 

IOO 

62 

6.6 

3 

IOO 

70 

3-8 

57% 

M. 

M. 

M. 

M. 

M. 

69.1 

3-6 

73-9 

2.2 

79% 

M.V. 

M.V 

M  V 

M.V. 

M.V. 

5-6 

i-9 

5-6 

.8 

21% 

.asked  to  count  them  independently,  and  then  the  average  of  the  results 
was  taken  as  the  position  for  the  rider  to  give  the  desired  difference. 
For  striking  the  forks,  a  felt  mallet  20.5  cm.  in  length  was  used.  It 
was  found  to  be  quite  difficult  to  strike  the  forks  evenly  with  this 
mallet,  but  after  a  considerable  amount  of  practice  it  was  possible  to 
give  practically  the  same  amplitude  to  the  vibration.  Whatever 
slight  deviations  may  have  occurred  were  equally  distributed  in  the 
two  positions  of  the  body  and  would  tend  to  balance  each  other.  The 
effort  was  constantly  made  also  to  strike  the  forks  in  precisely  the 
.same  relative  positions  so  as  to  produce  the  same  quality  of  tone  in 
every  test.  The  forks  were  also  sounded  in  a  position  relatively  the 
same  to  the  ear,  whether  the  body  was  in  the  horizontal  or  vertical 
position.  A  Mosso's  balance  was  provided  by  the  Columbia  Labora- 
tory, upon  which  all  the  subjects  in  this  series  were  tested,  and  the 
forks  were  placed  on  a  small  table  five  feet  from  the  axle  of  the  balance, 
.and  at  the  same  height  as  the  axle.  This  made  the  stimulus  at  an 
equal  distance  from,  and  in  the  same  relative  position  to,  the  ear  in 
both  positions  of  the  body.  All  the  tests  were  made  in  the  sound 


26 


INFLUENCE  OF  BODILY  POSTURE 


room  in  the  Columbia  Laboratory,  which  is  practically  free  from  all 
disturbing  stimuli. 

In  interpreting  the  results  of  this  table,  little  need  be  said.  There 
is  a  remarkable  similarity  to  the  results  of  the  preceding  table.  There 
are  only  five  subjects  who  could  discriminate  better  in  the  horizontal 
than  the  vertical  posture,  and  two  of  these,  D.  and  L.  C.  S.,  do  practi- 
cally the  same  in  both  positions.  All  others  show  a  very  marked 
tendency  to  discriminate  better  in  the  vertical  posture.  For  the  whole 
group,  discrimination  is  about  1.41  times  as  accurate  in  the  vertical 
as  the  horizontal.  Out  of  the  nineteen  subjects  tested  in  this  group 
five  were  selected  for  further  practice,  who  had  shown  the  greater 
difference  in  the  two  positions.  It  was  thought  that  if  the  great 
difference  found  was  due  to  association  and  habit,  a  definite  amount 
of  practice  would  tend  to  reduce  the  difference,  and  this  was  found 
to  be  the  case.  Table  IV  illustrates  this  point. 

TABLE  IV 

Effect  of  practice  upon  five  subjects  chosen  from  those  whose  records  are 
given  in  Table  III. 


Horizontal 

Vertical 

Subject 

A 

Number  of 
experi- 
ments 

Per  cent 
right  after 
practice 

P.B. 
after 
practice 

A 

Number 
of  ex- 
peri- 

Per  cent 
right  after 
practice 

P.E. 

after 
practice 

Com- 
para- 
tive 
per 

cents 

F.L.W. 

I 

350 

71 

1.2 

i 

200 

80 

.8 

67% 

W.H.S. 

2 

350 

74 

2.  I 

2 

200 

83 

14 

67% 

E.L.M. 

3 

400 

72 

3-5 

3 

250 

77 

2.  7 

77% 

L.F.F. 

2 

300 

6l 

4.8 

2OO 

65 

3-5 

73% 

B. 

3 

300 

63 

6.1 

3 

300 

69 

4.0 

65% 

M. 

M. 

M. 

M. 

M. 

68.2 

3-5 

74-8 

2-4 

69% 

M.V. 

M.V. 

M.V. 

M.V. 

M  V 

4-9 

1-5 

6.2 

i  .  i 

4% 

The  practice  effects  shown  in  Table  IV  can  best  be  summed  up  by 
a  comparison  of  the  last  columns  in  the  two  tables.  Subject  L.  F.  F. 
increased  his  comparative  per  cent,  from  48  to  73.  Subject  F.  L.  W. 
from  58  to  67.  Subject  W.  H.  S.  from  56  to  67.  Subject  E.  L.  M. 
from  69  to  77.  Subject  B.  from  57  to  65.  It  is  evident  that  this 
increase  in  the  comparative  per  cents,  could  be  brought  about  either 
by  improvement  in  the  horizontal  position,  by  doing  worse  in  the 
vertical  position,  or  by  doing  better  in  both  positions,  but  improving 
more  in  the  horizontal  position  than  in  the  vertical.  The  latter  seems 
to  be  the  case.  A  comparison  of  the  percentage  of  right  cases  of  these 
subjects  in  the  two  tables  reveals  the  fact  that  there  is  a  little  improve- 


DISCRIMINATION  OF  PITCH 


27 


ment  in  the  vertical  position,  but  nothing  to  be  compared  with  the 
improvement  made  in  the  horizontal.  This,  of  course,  would  reduce 
the  differences  in  the  probable  errors. 

In  this  selected  group,  however,  after  the  practice  indicated  in  the 
table,  there  still  remains  a  difference  greater  than  shown  in  any  other 
group  tested.  The  mean  probable  error  in  the  horizontal  position 
is  about  1.48  times  as  large  as  that  in  the  vertical.  It  may  be  remarked 
that  the  writer  believes  the  practice  effects  were  carried  to  their  limits 
in  these  subjects.  The  tests  were  carried  on  till  there  seemed  to 
be  no  further  improvement  in  either  position,  though  this  limit  was 
reached  more  quickly  in  the  vertical  than  in  the  horizontal  position. 
Consequently,  there  seemed  to  be  some  conditions  other  than  habit 
and  association,  which  make  subjects  discriminate  pitch  better  in  the 
vertical  than  in  the  horizontal  posture.  This  may  be  physiological, 
though,  as  has  been  stated,  there  is  no  good  ground  for  supposing  that 
sound  waves  would  effect  the  organ  of  hearing  any  better  in  one 
position  than  in  the  other. 

It  only  remains  to  sum  up  in  one  final  table  the  total  results  of  this 
investigation  of  the  discrimination  of  pitch. 

TABLE  V 

Average  probable  errors,  percentage  of  right  cases,  and  comparative  percents 
taken  from  Tables  I,  II,  and  III. 


Horizontal 

Vertical 

Per  cent  right 

P.  B. 

Per  cent  right 

P  E. 

Comparative  per  cents. 

M. 

M. 

M. 

M. 

74-5 

3-2 

78.7 

2.2 

83% 

M.V. 

M.V. 

M.V. 

M.V. 

4-4 

i-4 

6-5 

.8 

CHAPTER  V 


TACTILE   DISCRIMINATION 

Methods  and  Apparatus.— In  the  experiments  described  in  this 
chapter,  the  effort  was  made  to  find  whether  there  is  a  general  tendency 
on  the  part  of  a  group  of  subjects  to  have  finer  tactile  discrimination 
in  one  position  of  the  body  than  in  another.  The  method  here  used 
was  that  of  right  and  wrong  cases,  as  in  the  discrimination  of  pitch. 
However,  it  was  slightly  modified  in  form  to  suit  the  use  of  the  aesthes- 
iometers.  After  a  good  deal  of  preliminary  experimentation,  it  was 
found  that  practically  all  subjects  can  perceive  a  difference  of  1  mm. 
with  a  large  percentage  of  right  cases,  if  touched  upon  the  forehead  with 
two  aesthesiometers  whose  points  are  respectively  18  and  19  mm. 
That  is  to  say,  they  can  perceive  in  a  large  percentage  of  trials  that 
the  points  in  the  two  aesthesiometers  are  not  the  same  distance  apart, 
but  will  not  be  able  to  state  whether  the  distance  in  the  second  is 
greater  or  less.  This  fact  having  been  worked  out  experimentally, 
two  aesthesiometers  were  made  in  the  Columbia  Laboratory,  having 

TABLE  VI 

Results  of  tests  made  on  sixteen  students  of  Columbia  University  in  tactile 
discrimination,  by  the  use  of  aesthesiometers. 


Horizontal 

Vertical 

Subject 

Sex 

A 

Number 
of  ex- 
peri- 
ments 

Per 
cent 
right 

P.E. 

A 

Number 
of  ex- 
pert- 

incuts 

Per 
cent 
right 

P.E. 

Com- 
para- 
tive per 
cents 

M. 

Male 

IOO 

85 

•65 

IOO 

76 

•95 

146% 

B. 

IOO 

70 

.28 

IOO 

60 

•63    205% 

K. 
H. 

IOO 
IOO 

ii 

.00 

•45 

IOO 
IOO 

75 
72 

.00 
.16 

T?° 

Me. 

IOO 

72 

.16 

IOO 

65 

•75 

s. 

150 

88 

•57 

150 

76 

•95  (166% 

F. 

Female 

80 

74 

•05 

80 

70 

.28   1121% 

F/ 

Male 

IOO 

70 

.28 

IOO 

70 

.28 

I  OO% 

L. 

Female 

IOO 

79 

•83 

IOO 

67 

•54 

185% 

F.* 

Male 

IOO 

66 

.64 

IOO 

.54   276% 

2 

• 

IOO 

65 

•75 

IOO 

61 

.44  (139% 

J. 

" 

150 

74 

•05 

150 

66 

•64    155% 

S/ 

Female 

150 

72 

.16 

150 

64 

.88  |i62% 

D. 

Male 

IOO 

68 

•45 

IOO 

78 

.87     60% 

M/ 

" 

IOO 

74 

05 

IOO 

66 

1.64 

156% 

T    / 

100 

70 

.28 

IOO 

65 

1-75 

137% 

M. 

M. 

M. 

M. 

M. 

73 

1.16 

68 

i  .  i 

146% 

M.V. 

M.V. 

M.V. 

M.V 

M.V. 

4-6 

•24 

5-2 

•59 

36% 

TACTILE  DISCRIMINATION  29 

their  points  respectively  18  and  19  mm.  apart.  The  method  employed 
was  to  place  the  subject  on  the  Mosso  instrument  in  the  horizontal 
position,  and  touch  the  forehead  on  opposite  sides  of  the  median  line 
with  the  points  of  one  of  the  aesthesiometers,  and  then  after  an  interval 
of  two  seconds,  to  touch  the  forehead  in  approximately  the  same  place 
with  the  other.  The  subject  was  then  asked  to  state  whether  the 
points  of  the  second  were  further  apart  or  closer  together  than  the 
first.  By  this  means  a  table  similar  to  the  one  for  the  discrimination 
of  pitch  was  obtained.  There  was  one  difficulty  in  the  method  which 
seemed  quite  hard  for  subjects  to  overcome,  and  which  may  be  worth 
mentioning;  namely,  some  subjects  claimed  to  be  able  to  make  a 
judgment  of  the  distance  of  the  points  as  soon  as  the  first  stimulus 
was  given.  It  was  proven  by  actual  trial,  however,  in  all  the  cases 
where  this  difficulty  arose,  that  the  subjects  were  not  at  all  accurate 
in  these  judgments;  nevertheless,  they  seemed  to  influence  the  results 
somewhat.  However,  whatever  constant  errors  appear  here  from 
this  cause,  are  equally  distributed  in  the  two  positions,  for  the  subject 
was  rotated  to  the  opposite  position  after  every  five  tests.  Fatigue 
entered  very  largely  in  these  tests.  For  this  reason  only  a  few  ex- 
periments could  be  made  at  one  tune,  and  a  camel's  hair  brush  was 
used  to  slightly  sweep  over  the  forehead  after  each  experiment.  This 
seemed  to  dispel  the  fatigue  temporarily,  and  to  stimulate  the  tactile 
organs.  These  tests  were  not  hurried,  but  throughout  them  great 
deliberation  was  used.  While  only  two  seconds  intervened  between 
the  two  stimuli  upon  which  judgment  was  to  be  rendered,  plenty  of 
time  was  taken  between  the  two  consecutive  experiments  to  allow  all 
the  imagery  of  the  previous  test  to  disappear.  When  it  was  found 
that  the  subjects  were  confusing  the  actual  sensation  from  the  two 
points,  with  the  previous  images,  the  experimentation  was  concluded 
for  that  day. 

Interpretation  of  Results. — It  seems  quite  difficult  to  offer  any 
satisfactory  theory  for  the  results  found  in  this  table.  For  this  special 
group,  the  horizontal  position  is  decidedly  favorable  for  tactile  dis- 
crimination. Only  two  of  the  subjects  out  of  the  sixteen  can  dis- 
criminate better  in  the  vertical,  while  two  others  have  precisely  the 
same  ability  in  the  two  positions.  All  of  the  others  show  remarkable 
preference  for  the  horizontal,  ranging  in  comparative  per  cents  from 
121  to  276.  The  means  of  the  probable  errors  of  this  group  have  about 
the  same  relation  to  each  other  as  those  of  the  preceding  tables  on 
discrimination  of  pitch,  but  in  an  inverse  ratio. 

As  was  stated  previously,  a  theoretical  explanation  of  these  results 
is  somewhat  dangerous,  and  must,  of  necessity,  be  rather  arbitrary. 
The  horizontal  position  seems  favorable  to  the  free  flow  of  blood  to  all 
parts  of  the  body. '  In  this  position,  too,  not  having  to  overcome  the 


30  INFLUENCE  OF  BODILY  POSTURE 

effects  of  gravity,  the  blood  would  naturally  tend  to  flow  away  from  the 
great  splanchnic  area,  and  in  its  general  distribution,  more  of  it  would 
be  supplied  to  the  skin.  It  is  even  noticeable,1  when  subjects  are 
rotated  from  the  vertical  to  the  horizontal  position,  that  the  face  colors 
slightly,  due  to  an  extra  flow  of  blood  there.  Howell2  has  shown 
that  when  a  subject  assumes  the  horizontal  position  and  closes  his 
eyes  in  the  attempt  to  go  to  sleep,  those  portions  of  the  arm  within 
a  plethysmograph  undergo  dilation.  This  dilation  increases  as  sleep 
becomes  more  profound,  showing  that  the  skin  and  external  organs 
were  gorged  with  blood  during  sleep  and  horizontality.  Whether 
this  change  in  the  circulation  of  the  blood  is  the  cause  of  sleep  or  the 
result  of  it,  is  difficult  to  say,  but  it  seems  to  be  quite  plausible  to  sup- 
pose that,  if  in  the  horizontal  posture  there  is  an  extra  flow  of  blood 
to  the  skin,  the  tactile  organs  would  be  stimulated  somewhat  and 
would  discriminate  better.  It  may  be  said,  on  the  other  hand,  that  in 
this  position  the  brain  becomes  anaemic,  and  there  would  be  no  reason 
to  suppose  that,  even  if  the  sense  organs  were  more  active,  the  central 
processes  would  be  any  more  efficient.  This  argument  might  be 
answered  in  this  way:  sleep  does  ensue  after  a  long  time  when  the 
horizontal  position  is  assumed,  and  all  sensations  are  shut  out  as 
much  as  possible,  and  anaemia  of  the  brain  does  accompany  sleep  in 
rather  a  definite  ratio  to  its  depth.  But  in  the  experiments  under 
consideration,  the  subject  was  kept  in  the  state  of  attention  all  the 
time,  and  there  was  no  tendency  to  fall  asleep.  Besides  the  subject 
was  not  allowed  to  remain  in  the  horizontal  position  long  enough, 
according  to  the  authorities,  to  cause  the  anaemic  condition  of  the 
brain.  On  the  other  hand,  the  blood  pressure  changes  almost  imme- 
diately upon  the  change  of  posture,  and  the  skin  is  thoroughly  stimu- 
lated with  fresh  blood.  If  it  is  true,  as  has  been  shown  in  the  chapter 
dealing  with  the  literature  of  this  subject  by  Vaschide  and  others, 
that  an  increased  flow  of  blood  to  an  organ  increases  its  sensibility, 
then  the  results  of  this  table  seem  to  have  a  sound  physiological  basis. 
We  would  expect  superior  sense  qualities  in  the  skin,  if  by  any  means 
its  blood  supply  is  increased. 

1  Manaceine,  Sleep,  Its  Physiology,  Pathology,  Hygiene,  and  Psychology,  Chap.  I. 
*  W.  H.  Howell,  Jour  of  Exp.  Med.,  Vol.  II,  No.  3,  1897. 


CHAPTER  VI 

A   COMPARISON  OF  ADDING  ABILITY   IN  THE  HORIZONTAL  AND  VERTICAL 
POSITIONS  OF  THE  BODY 

The  experimental  study  with  which  this  chapter  deals  was  an 
attempt  to  discover  whether  there  is  any  marked  tendency  on  the  part 
of  individuals  to  carry  on  such  mental  processes  as  are  involved  in 
addition,  better  in  one  position  than  in  another.  The  method  must,  of 
course,  be  somewhat  similar  to  that  employed  in  the  previous  tests. 
Problems  of  equal  difficulty  were  given  for  solution  in  the  two  posi- 
tions of  the  body,  and  the  results  statistically  compared.  This  was  the 
method  used  in  all  three  of  the  series  represented  by  Tables  VII,  VIII, 
and  IX,  in  this  chapter. 

The  tests  made  upon  the  school  children  were  not  exactly  under 
laboratory  conditions,  but  the  writer  believes  were  sufficiently  so 
to  be  valid.  All  the  experiments  were  made  in  a  quiet  room,  well 
lighted,  and  free  from  distracting  stimuli.  In  place  of  the  Mosso 
instrument,  a  cot  was  used  for  the  horizontal  posture,  and  the  subjects 
were  asked  to  stand  up  for  the  tests  made  in  the  vertical  posture.  In 
•every  case  the  subject's  eyes  were  in  the  same  relative  position  to  the 
light  in  the  two  positions  of  the  body,  so  that  there  was  no  chance  for 
the  figures  on  the  card  to  be  better  lighted  in  one  position  than  in 
-another.  The  problems  were  theoretically  of  equal  difficulty.  Each 
problem  contained  the  same  digits  an  equal  number  of  times,  but  in 
entirely  different  combinations.  The  following  was  one  of  the  prob- 
lems used  for  the  children  in  their  tests:  1,  3,  5,  4,  2,  6,  2,  3,  5,  1,  6,  4, 
5,  2,  1,  6,  4,  3,  5,  4,  1,  6,  3,  2.  These  digits  were  arranged  in  a  vertical 
column,  to  be  added  aloud  in  every  case  from  bottom  to  top.  It  will 
be  noticed  that  each  of  the  six  digits  recur  in  this  problem  four  times, 
.and  that  with  the  same  digits  used  the  same  number  of  times  a  great 
variety  of  combinations  can  be  obtained,  making  the  problems  theoret- 
ically of  equal  difficulty.  Of  course,  the  answers  to  all  the  problems 
were  the  same.  Subjects  were  told  the  character  of  the  problems  in 
the  beginning  of  the  experimentation,  and  that  the  answers  were  all 
the  same.  They  were  also  told  that  all  errors  would  be  recorded  in 
the  adding  process,  and  that  therefore  the  mere  obtaining  of  the  correct 
answer  was  a  small  matter,  if  errors  were  made  in  the  process.  Sub- 
jects were  then  made  to  add  aloud,  beginning  at  the  bottom  of  the 
column  of  figures,  which  were  placed  on  a  card  three  by  eight  inches. 
The  sub-total  for  each  digit  was  required  to  be  given,  thus  allowing  for 
only  single  combinations.  On  a  duplicate  card,  which  was  held  by 
the  experimenter,  all  the  sub-totals  were  arranged  from  the  bottom 


32 


INFLUENCE  OF  BODILY  POSTURE 


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ADDING  ABILITY 


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INFLUENCE  OF  BODILY  POSTURE 


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ADDING  ABILITY  35 

upward,  so  that  all  errors  were  easily  detected.  In  this  first  series, 
the  method  of  exposure  was  rather  crude.  The  subject  was  asked  to 
close  his  eyes,  holding  the  card  in  his  hand  upon  which  was  the  prob- 
lem to  be  added.  At  a  given  signal,  he  opened  his  eyes  and  added 
as  fast  as  he  could.  A  stop-watch  recorded  the  time  from  which  he 
named  the  first  digit  until  the  result  was  announced.  A  strict  record 
of  all  errors,  their  number  and  size,  and  whether  positive  or  negative, 
was  kept,  and  they  are  shown  in  the  accompanying  tables. 

An  explanation  of  certain  parts  of  Table  VII  is  necessary.  Under 
the  column  "time,"  will  be  found  the  mean  for  each  subject  to  add 
the  number  of  problems  opposite  his  name,  and  also  the  variation 
from  this  mean.  Under  "Errors"  are  recorded  the  number  and  size 
of  all  errors,  and  whether  they  are  positive  or  negative.  For  example, 
after  M.  A.'s  name  it  will  be  observed  that  in  the  24  problems  which 
he  added,  he  made  7  positive  errors,  and  2  negative  of  one  point  each. 
He  also  made  4  positive  errors  of  two  points  each,  and  1  positive  error 
of  three  points.  In  addition  to  these,  he  made  one  positive  error  of  ten 
points. 

The  result  of  this  series  of  tests  is  readily  seen  from  the  mean  times 
of  adding  all  the  problems  in  the  two  positions,  and  from  the  total 
errors  in  each  position.  The  mean  time  for  the  horizontal  position 
is  31.5  seconds,  while  it  is  32.7  for  the  vertical  position.  There  was  a 
total  of  61  errors  made  in  the  horizontal  position,  and  a  total  of  78 
made  in  the  vertical.  This  shows  a  slight  advantage  for  the  horizontal 
position.  As  is  to  be  expected,  these  differences  are  rather  close;  but 
it  is  believed  by  the  writer  that  the  test  is  sufficiently  fine  to  bring  out 
any  real  differences  that  are  to  be  found  in  the  adding  process  in  the 
two  positions  of  the  body.  Undoubtedly,  the  table  does  show  a  decided 
advantage  for  the  horizontal  position,  which  will  be  further  shown  in 
the  two  following  tables. 

The  results  of  Table  VIII  do  not  seem  to  vary  much  from  those 
found  in  Table  VII.  The  mean  time  of  adding  all  the  problems  in  the 
horizontal  position  is  39.4  seconds,  and  for  the  vertical  is  40.5.  The 
number  of  errors  is  60  in  the  horizontal,  and  70  in  the  vertical.  Here 
again  is  a  decided  advantage  in  favor  of  the  horizontal  position  for 
the  adding  process. 

It  should  be  stated  that  with  the  above  subjects  the  Mosso  balance 
was  used  for  rotating  the  subject  from  one  position  to  another,  and 
that  the  problems  were  harder,  because  of  the  fact  that  the  digits  4, 
5,  6,  7,  8,  9  were  used  in  various  combinations  for  forming  the  prob- 
lems instead  of  1,  2,  3,  4,  5,  and  6.  This  accounts  for  the  fact,  which 
appears  in  the  table,  that  the  adults  in  the  table  added  more  slowly 
than  the  children  represented  in  Table  VII.  The  children  probably 
would  have  added  the  latter  series  much  more  slowly,  but  the  ratio 


36  INFLUENCE  OF  BODILY  POSTURE 

between  the  results  of  the  two  positions  of  the  body  as  represented 
in  the  two  tables  is  not  very  different. 

All  the  tests,  the  results  of  which  are  found  in  Table  IX,  were 
made  in  the  Columbia  Laboratory,  and  the  subjects  were  mostly  psycho- 
logical students,  though  some  were  used  from  other  departments  in 
the  University.  The  tests  were  made  in  a  dark  room  so  that  the 
quantity  of  light  could  be  regulated  in  the  two  positions  of  the  body. 
A  sixteen  candle  power  incandescent  light  was  attached  to  the  head 
of  the  Mosso  instrument,  which  rotated  with  it,  and  thus  furnished 
the  subject  with  the  same  quantity  of  light  in  both  positions.  At  a 
given  signal  this  light  was  turned  on,  and  the  subject  began  to  add 
as  rapidly  as  he  could.  The  stop-watch  was  started  at  the  pronouncing 
of  the  first  digit,  and  stopped  when  the  result  was  announced.  It 
was  found,  however,  fully  as  satisfactory  to  have  the  subject  close 
his  eyes  till  the  signal  was  given,  and  this  method  was  largely  used. 
In  every  case,  the  actual  adding  process  was  timed,  and  the  averages 
taken  for  the  total  number  of  problems. 

In  this  series  of  tests,  only  two  subjects  did  better  in  the  vertical 
posture,  while  the  ratio  between  the  means  of  all  fourteen  subjects  in 
the  two  positions  coincides  very  closely  with  the  results  of  the  pre- 
vious tables.  The  horizontal  mean  time  is  26.3  and  the  vertical  is 
27.5.  The  total  number  of  errors  in  the  horizontal  position  is  49,  and 
in  the  vertical  71. 

Some  comment  upon  certain  phenomena  which  manifested  them- 
selves during  these  adding  tests  seems  necessary.  Most  of  the  subjects 
used  were  quite  susceptible  to  fatigue  in  these  tests,  so  it  was  deemed 
advisable  when  testing  the  Columbia  students,  to  alternate  the  adding 
test  with  the  tapping  test,  which  will  be  explained  in  Chapter  IX. 
By  this  means,  the  attention  was  not  held  directly  upon  the  adding 
test  longer  than  the  adding  of  two  problems,  and  then  the  subject  was 
rotated  to  the  opposite  position  and  started  off  with  the  tapping  test. 

By  this  alternation,  it  is  thought  that  very  little  adding  fatigue 
appeared,  and  what  did  was  equally  distributed  in  the  two  positions 
of  the  body.  In  any  particular  subject,  it  was  noticed  that  the 
speed  of  adding  was  materially  lessened  as  experimentation  went  on. 
The  practise  effect  from  day  to  day  on  some  of  the  subjects  was 
quite  marked,  some  improving  in  rapidity  during  the  series  as  much  as 
thirty  per  cent.  A  few  did  not  improve  at  all,  and  some  did  worse  at  the 
close  of  the  series.  One  feature  in  the  experiments  was  quite  noticeable 
with  two  of  my  subjects.  They  would  apparently  become  confused 
toward  the  close  of  the  column  and  make  a  sudden  stop,  having  for- 
gotten the  sub-total  and  not  being  able  to  proceed.  This  did  not 
seem  to  be  due  to  fatigue,  for  their  records  after  such  experiences  were 
as  good  or  better  than  before.  It  appeared  to  be  related  to  stage 


ADDING  ABILITY  37 

fright,  and  was  a  temporary  loss  of  memory.  Another  interesting 
fact  appeared  with  reference  to  the  relative  time  to  solve  problems 
when  errors  were  made  and  when  not.  It  was  found  that  in  the  prob- 
lems in  which  the  greatest  speed  was  attained  no  errors  were  made, 
but  errors  usually  appear  more  frequently  when  the  subject  was  adding 
slower  than  his  usual  rate.  The  table  reveals  another  very  remarkable 
thing  in  regard  to  the  character  of  the  errors.  Out  of  a  total  of  389 
errors,  355  are  positive,  and  only  34  are  negative.  The  writer  can- 
not account  for  this  tendency  in  nearly  all  adders  to  overestimate 
rather  than  to  underestimate.  That  it  is  a  rather  universal  tendency 
among  all  the  subjects  tested  is  shown  clearly  by  a  mere  glance  at 
either  of  the  three  tables.  It  will  be  noticed  that  the  errors  are  mostly 
one  point  and  two,  with  a  good  scattering  of  tens.  However,  the 
making  of  an  error  of  ten  in  the  adding  process  is  really  the  equivalent 
of  an  error  of  one.  It  is  merely  a  memory  lapse  in  passing  from  one 
number  in  ten's  order  to  another  above.  It  must  be  said  that  any 
method  of  treatment  of  the  valuation  of  errors  in  such  tests  is  arbitrary, 
and  in  the  present  discussion  entirely  useless. 

The  method  of  adding  aloud  was  very  troublesome  to  some  subjects, 
but  was  the  only  means  of  making  complete  records  of  all  the  errors. 
It  should  be  said  also  that  no  subject  was  allowed  to  make  combina- 
tions of  numbers  above  the  sub-total  in  mind  and  the  number  imme- 
diately above.  Every  sub-total  had  to  be  spoken  aloud,  so  that  in 
case  an  error  had  been  made,  it  could  be  recorded. 

Summing  up  the  total  results  for  the  three  tables  previously  given, 
we  find  that  the  mean  time  for  all  problems  solved  in  the  horizontal 
position  is  30.6  seconds,  and  for  the  vertical  position  it  is  31.7.  The 
total  number  of  errors  in  the  horizontal  is  170,  and  for  the  vertical  219. 
These  figures  measure  accurately  the  subjects  tested  upon  their  ability 
to  carry  on  the  adding  process  in  these  two  positions  of  the  body, 
and  indicate  a  marked  preference  for  the  horizontal  position. 

Any  explanation  of  this  fact  will  be  pure  theory.  It  seems,  how- 
ever, from  the  considerations  in  Chapter  II  on  blood  pressure,  and 
cerebral  circulation,  that  there  is  a  somewhat  more  favorable  oppor- 
tunity in  the  horizontal  posture  for  a  free  circulation  of  the  blood 
through  the  brain,  and  consequently  for  the  stimulation  of  the  centers 
involved  in  the  adding  processes.  This,  together  with  the  fact  that 
all  muscular  tension  is  relaxed,  the  body  is  perfectly  at  rest,  and  the 
effects  of  gravity  are  not  operating  upon  the  blood  vessels  of  the 
splanchnic  area,  thus  allowing  a  freer  distribution  of  blood  to  all  parts 
of  the  body,  seems  to  offer  the  only  explanation  possible.  Certainly 
such  a  condition  would  not  be  favorable  to  muscular  activity,  as  will 
be  shown  in  another  chapter,  but  there  are  some  reasons  why  it  should 
be  considered  favorable  for  the  deeper  mental  processes. 


CHAPTER  VII 

A  COMPARISON   OP    PULSE  RATE,  BLOOD  PRESSURE,  AND  VISUAL  MEMORY 
IN  THE  HORIZONTAL  AND  VERTICAL  POSITIONS  OF  THE  BODY 

The  solution  of  two  separate  problems  is  undertaken  in  this  chapter. 
First,  a  comparison  of  the  three  tests — blood  pressure,  heart-beat,  and 
visual  memory — is  made  for  the  two  positions  of  the  body,  somewhat  in 
the  manner  of  the  previous  tests.  Second,  the  effort  is  made  to  corre- 
late the  mental  tests  with  physical  conditions.  The  latter  was  deter- 
mined by  the  method  employed  by  Dr.  Crampton,  Assistant  Superin- 
tendent of  Physical  Training  in  the  New  York  City  schools,  and  con- 
sists in  a  grading  of  the  subjects  as  A,  B,  C,  D,  E,  F,  G,  H,  and  I,  ac- 
cording to  the  relative  blood  pressure  and  heart-beat  in  the  two  posi- 
tions of  the  body.  Thus  as  he  states : 

"The  total  change  of  blood  pressure  in  those  who  may  be  con- 
sidered in  health  is  from  plus  10  mm.  to  minus  10  mm.  Hg.  That  of 
pulse  rate  is  from  plus  5  to  plus  35."  Dr.  Crampton  then  states  that 
it  is  possible  to  divide  the  whole  range  of  individuals  into  fifths,  and 
he  constructs  a  tentative  table  in  which  the  letters  constitute  the 
index  to  the  splanchnic  efficiency  as  follows: 

Blood  pressure  increase  + 10     +5        o        — 5    — 10 


(    5 

A 

B 

C 

D 

E 

12 

B 

C 

D 

E 

F 

Increase  in  heart  rate     •{  20 

C 

D 

E 

F 

G 

I  28 

D 

E 

F 

G 

H 

I  35 

E 

F 

G 

H 

I 

The  above  grades  then  constitute  a  sort  of  index  to  the  splanchnic 
efficiency  of  the  individual,  and  it  is  believed  give  a  valid  gradation  of 
individuals  with  reference  to  their  physical  condition. 

At  any  rate  I  have  accepted  the  results  obtained  by  Dr.  Crampton 
as  valid,  and  have  performed  the  tests  for  blood  pressure  and  heart- 
beat according  to  his  directions.  All  my  subjects  who  were  tested 
for  visual  memory  were  at  the  same  time  tested  as  to  heart-beat  and 
blood  pressure,  the  experiments  alternating  in  the  following  order: 
First,  heart-beat;  second,  blood  pressure;  and  third,  visual  memory. 

The  method  of  taking  this  extended  series  of  tests  should  be  ex- 
plained in  detail.  All  of  the  tests  were  made  in  one  of  the  sound  rooms 
in  the  Columbia  University  Laboratory,  which  is  also  a  dark  room. 
Here  it  was  possible  to  regulate  the  light,  as  in  the  previous  tests,  by 
attaching  an  incandescent  lamp  of  sixteen  candle  power,  directly  to 
the  head  of  the  Mosso  instrument,  and  in  a  favorable  position  to  shade 
the  eyes  and  yet  shine  directly  upon  the  card-holder  placed  in  the 
proper  position  in  front  of  the  eyes.  The  cards  upon  which  were  the 


PULSE  RATE,  BLOOD  PRESSURE,  ETC.  39 

digits  to  be  visually  remembered  were  equally  illuminated,  and  in 
the  same  relative  position  to  the  eyes  in  both  positions  of  the  body. 
The  order  in  which  the  experiments  were  made  was  as  follows:  The 
subject  was  first  placed  on  the  balance  in  the  horizontal  position,  and 
after  having  remained  there  for  about  two  minutes,  so  that  the  circu- 
latory organs  were  completely  adjusted  to  this  position,  the  pulse- 
was  counted,  the  full  number  per  minute.  The  systolic  blood  pressure 
was  then  taken;  the  instrument  used  for  this  purpose  was  the 
Riva-Rocci  sphygmomanometer.  Care  was  taken  to  take  these 
measurements  in  the  manner  prescribed  by  Dr.  Crampton  hi  his  tests 
upon  the  school  athletes  of  the  New  York  City  schools.  It  is  thus 
possible  to  grade  the  subjects  physically  as  he  did,  and  to  compare 
their  physical  condition  with  mental  ability.  After  these  two  physical 
tests  were  made  and  recorded,  the  visual  memory  test  followed.  For 
this  experiment,  cards  two  and  a  half  inches  by  seven  inches  were 
prepared,  upon  which  eleven  digits  were  placed  in  rather  large  figures, 
lengthwise  of  the  card.  The  following  is  an  example  of  one  of  the 
series  of  digits  to  be  learned  visually:  7,  1,  3,  5,  9,  6,  2,  8,  4,  1,  3.  The 
card  was  then  placed  in  the  card-holder  directly  in  the  field  of  vision 
of  the  subject,  and  at  a  given  signal  was  exposed  to  view  for  four 
seconds.  He  was  asked  to  learn  them  visually  from  left  to  right,  if 
not  all,  as  many  as  he  could  in  the  four  seconds.  Subjects  were  cau- 
tioned not  to  use  lips,  tongue,  palate,  or  even  muscular  imagery  of  the 
digits  to  be  learned,  and  at  end  of  four  seconds  the  exposure  ceased, 
and  he  was  asked  immediately  to  repeat  the  digits  in  the  order  learned 
from  right  to  left.  A  record  was  kept  of  those  digits  correctly  given. 
After  a  few  seconds,  the  card  was  exposed  a  second  time  and  the  sub- 
ject asked  to  renew  his  efforts  to  learn  the  series.  This  was  continued 
until  the  digits  were  correctly  given.  By  this  means  it  was  possible 
to  keep  an  accurate  record  of  all  errors  made  by  each  subject,  as  well 
as  the  number  of  trials  to  learn  the  series.  Both  of  these  facts  are 
taken  into  consideration  in  determining  the  mental  efficiency  in  visual 
memory  on  any  subject.  Then,  before  the  subject  was  elevated  to  the 
vertical  position,  the  heart-beat  and  blood  pressure  were  again  taken, 
so  that  by  the  greater  number  of  tests,  an  average  would  be  reached 
which  would  include  all  variations  due  to  change  hi  physical  condition 
or  any  other  causes. 

In  Table  X  are  embodied  the  results  of  the  long  series  of  tests 
previously  described.  In  visual  memory,  it  includes  630  tests  made 
upon  27  subjects,  and  for  blood  pressure  and  pulse  beat,  the  number 
of  tests  is  doubled,  for  the  reason  that  these  both  preceded  and  suc- 
ceeded each  visual  memory  test.  In  order  that  the  table  may  be  per- 
fectly clear,  some  explanation  may  be  necessary.  Take,  for  example, 
subject  "H,"  the  first  one  in  the  list.  Under  the  column,  "pulse  rate," 


40 


INFLUENCE  OF  BODILY  POSTURE 


TABLE  X 
Comparative  results  of  pulse  rate,  blood  pressure,  and  visual  memory  in  the  horizontal  and  vertical  positions  of  the  body. 

Memory- 
rank 

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| 

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Errors 

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PULSE  RATE,  BLOOD  PRESSURE,  ETC.  41 

the  mean  for  twenty  tests  in  the  horizontal  position  was  65,  with  a 
variation  of  3.  Under  the  column,  "blood  pressure,"  the  mean  for 
twenty  tests  in  the  horizontal  position  was  112.2,  and  the  mean  varia- 
tion 2.4.  Under  "visual  memory,"  by  the  use  of  ten  separate  cards, 
the  mean  number  of  trials  to  learn  the  series  of  eleven  digits  on  each 
card  was  5.3,  making  a  total  of  340  errors.  In  the  vertical  position, 
similar  columns  will  be  observed,  having  the  same  significance  as  those 
in  the  horizontal  position.  We  are  only  concerned  in  a  comparison 
of  the  results  in  the  two  positions. 

It  will  be  conceded,  I  think,  that  the  visual  memory  tests,  taking 
into  consideration  their  number  for  each  individual  subject,  and  that 
every  error  was  recorded,  and  that  the  table  indicates  the  average 
number  of  trials  to  learn  the  series  visually,  furnish  a  reliable  test  of  the 
ability  of  the  subjects  in  visual  memory.  Either  the  total  number  of 
errors  or  the  mean  trials  for  each  subject  make  a  sufficiently  fine 
test  to  enable  us  to  determine  with  precision  the  relative  ability  of 
these  subjects.  As  will  be  seen  later,  upon  the  basis  of  these  results, 
it  is  possible  to  divide  the  subjects  into  groups,  somewhat  after  the 
fashion  that  Dr.  Crampton  divided  his  subjects  for  physical  condition. 
The  actual  method  of  doing  this  was  to  arrange  the  records  for  visual 
memory,  found  in  Table  X,  in  a  series  beginning  with  the  lowest  and 
ending  with  the  highest.  By  dividing  the  difference  between  the 
highest  and  the  lowest  of  these  records  into  nine  equal  parts  we  secure 
a,  gradation  of  subjects  for  visual  memory  which  corresponds  to  the 
gradation  by  Dr.  Crampton  for  physical  condition,  as  A,  B,  C,  D,  E, 
F,  G,  H,  and  I.  When  this  is  done  it  is  then  only  necessary  to  divide 
them  into  groups  as  to  physical  condition  hi  precisely  the  same  number 
that  he  did,  in  order  to  correlate  the  two  groups  and  see  how  far  one 
is  coincident  with  the  other.  While  this  correlation  of  mental  and 
physical  tests  is  not  directly  involved  in  my  problem,  it  is  an  interesting 
side  light  upon  a  problem  which  has  been  attacked  by  several  writers 
and  may  suggest  a  fruitful  method  for  further  research.  The  usual 
method  which  has  been  employed  has  been  to  compare  the  grades 
obtained  by  college  or  university  students  in  their  academic  work 
with  the  grades  or  standing  in  the  department  of  physical  training. 
One  serious  objection  to  the  validity  of  such  comparison  is  that  the 
grades  thus  compared  are  upon  as  many  different  standards  as  there 
are  different  departments  and  professors.  It  has  been  proven1  that 
there  is  very  little  validity  in  grades  of  any  sort  unless  a  probable 
error  is  assigned,  and  this  would  be  much  more  so  when  a  large  number 
of  grades  are  compared  which  have  not  been  standardized.  The 
method  herein  employed  has  the  advantage  of  correlating  mental  and 
physical  tests  taken  at  the  same  time  and  under  the  same  extremely 

1  Cattell,  "Examinations,  Grades  and  Credits,"  Pop.  Sci.  Mon.,  Feb.,  1905. 


42 


INFLUENCE  OF  BODILY  POSTURE 


careful  laboratory  conditions.  All  tests  were  made  by  the  same  ex- 
perimenter, and  the  individuals  are  arranged  serially  into  groups  in 
precisely  the  same  manner  for  the  mental  as  for  the  physical  tests. 
Thus  as  nearly  as  possible,  the  two  groups  are  standardized,  being 
arranged  in  both  series  according  to  the  probability  curve,  which  is 
valid  for  most  mental  and  physical  characteristics. 
TABLE  XI 

Correlation  of  visual  memory  with  physical  condition,  by  method  of  unlike 
signs. 

As=r;B  =  2;  C  =  3;D  =  4;E  =  s;  F  =  6;G  =  7;  H=8. 


Rank 

Visual  memory 

Rank 

Physical  condition 

B 

2_ 

B 

2  

B 

2  

B 

2  

B 

2  

D 

4  + 

B 

2  

B 

B 

2  

C 

3— 

B 

2  

C 

3— 

C 

3— 

B 

c 

3— 

B 

2  

C 

3— 

D 

4+ 

c 

3—  - 

B 

c 

3— 

A 

i  — 

c 

3— 

C 

3— 

c 

3—  Median=3.87 

B 

2  —  Median  =3.  39 

D 

4  + 

D 

4+ 

D 

4  + 

F 

6  + 

D 

4+ 

A 

i  — 

D 

4  + 

C 

3— 

D 

4  + 

B 

D 

4  + 

C 

3— 

E 

5  + 

D 

4  + 

E 

5  + 

D 

4+ 

E 

5  + 

A 

i  — 

F 

6  + 

D 

4  + 

G 

7  + 

E 

5  + 

G 

7  + 

G 

7  + 

H 

8  + 

F 

6  + 

H 

8  + 

E 

5  + 

In  Table  XI  the  two  columns,  "physical  rank"  and  "memory 
rank,"  should  be  noted.  After  arranging  the  twenty-seven  subjects 
tested  into  eight  groups,  distinctly  marked  from  each  other  by  the 
results  of  the  tests  for  physical  condition  and  visual  memory,  it  was 
desired  to  find  how  far  the  individuals  found  in  the  several  groups 
for  physical  condition  were  also  found  in  the  corresponding  groups  for 
visual  memory.  In  other  words,  the  problem  was  to  determine  the 
correlation  between  the  physical  rank  and  visual  memory  of  the  twenty- 
seven  subjects  tested  in  the  two  series.  The  method  employed  was 
that  known  as  the  "method  of  unlike  signs."  By  reference  to  Table 
XI  it  will  be  observed  that  six  of  the  subjects  tested  in  visual  memory 
are  ranked  as  "B,"  seven  are  ranked  as  "C,"  six  as  "D,"  three  as 
"E,"  one  as  "F,"  two  as  "G,"  and  two  as  "H."  The  median  of  this 


PULSE  RATE,  BLOOD  PRESSURE,  ETC.  43 

series  of  numbers  is  found  to  be  3.87.  In  the  column  just  opposite  that 
of  visual  memory  is  found  the  rank  of  the  corresponding  individuals 
for  physical  condition.  The  median  of  this  series  of  numbers  is  3.39. 
The  signs  are  affixed  to  each  rank  in  both  columns,  negative  when 
below  the  median,  and  positive  when  above.  Comparing  the  signs  in 
the  two  series,  seven  are  unlike  or  25.9  per  cent,  of  the  whole  have 
unlike  signs.  Substituting  in  the  formula  r  =  cos  TT  U,  in  which  r  is  the 
coefficient  of  correlation,  and  U  the  per  cent  of  unlike  signs,1  we  get 
r=70.7  per  cent. 

From  Table  X  the  results  of  this  extended  series  of  tests  are  easily 
summed  up.  It  will  be  observed  that  the  mean  for  the  heart-beat  of 
all  subjects  tested  is  71.5  for  the  horizontal  position,  and  81.5  for  the 
vertical  posture.  Only  one  subject  in  this  group,  namely,  "D,"  has  a 
higher  rate  of  pulse  in  the  horizontal  than  in  the  vertical  position. 
Thus  the  whole  series  of  tests  as  well  as  those  of  the  succeeding  chapter 
show  clearly  that  there  is  a  tendency  to  an  increase  of  heart-beat 
when  the  body  is  elevated  from  the  horizontal  to  the  vertical  posture. 
The  same  general  tendency  holds  also  for  blood  pressure,  though  here 
we  find  one-third  of  the  subjects  having  a  higher  pressure  in  the  hori- 
zontal than  in  the  vertical  position.  This  is  an  indication,  as  has 
already  been  shown  in  Chapter  II,  that  in  these  subjects  the  vaso-motor 
mechanism  is  not  adequate  to  the  physical  adaptation  necessary  to 
counteract  the  effect  of  gravity  in  the  vertical  posture.  According 
to  Dr.  Crampton,  these  subjects  must  be  regarded  as  in  bad  physical 
condition.  From  the  percentage  of  correlation  already  found,  it  is 
seen  that  they  are  also  in  poor  mental  condition;  at  least  they  are  not 
efficient  in  the  mental  tests  herein  recorded.  The  mean  blood  pressure 
of  all  subjects  tested  for  the  horizontal  posture  is  118.1,  and  for  the 
vertical  it  is  121.8.  It  must  be  said  that  this  slight  difference  in  the 
two  positions  is  due  to  the  large  number  of  those  who  may  be  said  to 
be  abnormal  in  the  vaso-motor  mechanism. 

In  regard  to  the  memory  tests,  my  subjects  do  decidedly  better 
in  the  horizontal  position.  Only  six  out  of  twenty-seven  do  better 
in  the  vertical  position,  and  four  of  these  do  practically  the  same  in 
the  two  positions.  The  mean  trials  to  learn  the  series  in  the  horizontal 
posture  for  all  subjects  of  this  series  is  5.2  and  in  the  vertical  it  is  5.8. 
The  mean  errors  made  in  the  horizontal  posture  is  199  and  in  the  ver- 
tical it  is  236.  Taking  into  consideration  these  two  sets  of  averages, 
there  is  no  doubt  that  for  these  subjects  the  horizontal  position  is 
preferable  for  visual  memory. 

1  For  a  table  giving  the  values  of  r  corresponding  to  each  value  of  U,  the 
writer  is  indebted  to  Professor  Thorndike. 


CHAPTER  VIII 

A   COMPARISON  OF  PULSE  RATE,  BLOOD  PRESSURE,  AND   AUDITORY   MEM- 
ORY IN  THE  HORIZONTAL  AND  VERTICAL  POSITIONS  OF  THE  BODY 

Immediately  upon  the  completion  of  the  extended  series  of  tests 
recorded  in  the  previous  chapter,  the  writer  began  a  similar  series  on 
auditory  memory.  These  experiments  were  made  in  the  Columbia 
Laboratory,  and  under  the  same  conditions  as  the  preceding.  All 
were  made  in  one  of  the  sound  rooms,  which  is  also  a  dark  room.  The 
conditions  for  testing  auditory  memory  were  thus  most  favorable,  all 
other  stimuli  being  eliminated  as  nearly  as  possible.  As  in  the  pre- 
ceding chapter,  the  effort  is  made  to  find  the  correlation  between 
physical  condition  and  auditory  memory.  The  pulse  rate  and 
blood  pressure  are  taken  both  before  and  after  each  auditory  memory 
test,  in  both  positions  of  the  body,  so  as  to  insure  large  enough  an 
average  to  eliminate  any  physiological  variations  that  might  occur. 
The  method  is  thus  seen  to  be  practically  the  same  as  in  the  preceding 
chapter,  though  a  word  needs  to  be  said  concerning  the  method  of 
taking  the  auditory  tests. 

The  subject  was  placed  upon  the  Mosso  instrument  in  the  horizontal 
position,  and  after  the  heart- beat  and  blood  pressure  were  taken,  a 
series  of  eleven  digits  were  read  slowly  to  the  subject.  As  soon  as  the 
reading  had  finished,  he  was  asked  to  repeat  the  series  aloud,  beginning 
at  the  first  and  proceeding  as  far  as  he  could.  The  experimenter  was 
supplied  with  a  sheet  of  paper,  having  written  at  the  top  the  series 
read,  and  as  the  subject  repeated  the  digits  all  errors  were  carefully 
recorded.  This  was  not  a  difficult  matter,  for  when  an  error  was 
made,  having  the  series  directly  above,  the  experimenter  could  quickly 
check  off  the  digit  wrongly  repeated.  Eleven  digits  were  chosen  as 
about  the  right  length  of  series,  because  it  was  thought  that  no  subject 
could  learn  them  auditorily  in  one  reading.  This  was  found  to  be  the 
case,  though  the  subject  S."'  did  learn  one  or  two  of  the  series  in  one 
reading.  No  other  subject  was  able  to  learn  them  in  less  than  three 
readings.  Taking  into  consideration  the  number  of  times  for  each 
subject  to  learn  the  series,  and  the  number  of  errors  made,  the  test 
becomes  extremely  fine,  and  leaves  no  doubt  as  to  the  validity  of  the 
results  in  determining  the  auditory  memory  powers  of  the  subjects 
tested. 

It  should  be  remarked  that  all  subjects  were  cautioned  against 
learning  the  series  in  any  other  manner  than  auditorily.  They  were 
asked  to  inhibit  all  lip  movements,  movements  of  the  larynx  or  tongue, 
and  were  asked  to  refrain  from  any  visualizing  of  the  digits  after  hearing 


PULSE  RATE,  BLOOD  PRESSURE,  ETC.  45 

them,  so  as  to  aid  the  memory.  Of  course,  it  must  be  conceded  that 
this  is  totally  impossible  with  some  subjects,  and  it  is  entirely  probable 
that  no  one  remembers  in  a  purely  auditory  manner.  The  auditory 
impression  is,  for  most  individuals,  mixed  with  visual  imagery,  as  well 
as  muscular  and  tactual.  Still  the  writer  believes  that  the  test  is  valid 
for  auditory  memory,  so-called. 

It  should  also  be  remarked  that  the  fifteen  subjects  used  in  this 
series  were  trained  subjects,  having  had  the  experience  of  the  preceding 
tests.  Thus  we  have  here  a  very  convenient  means  of  making  com- 
parison of  visual  with  auditory  memory.  While  this  is  not  directly 
bearing  upon  my  problem,  it  is  worth  while  to  call  attention  to  the 
individual  differences  which  these  fifteen  subjects  exhibit.  For  ex- 
ample, Subject  "B"  learns  the  eleven  digits  visually,  in  the  horizontal 
position,  in  3.2  mean  trials,  while  in  the  same  position,  it  takes  him  7.9 
mean  trials  to  learn  the  similar  series  auditorily.  In  like  manner  sub- 
jects "L,"  "K,"  "A,"  and  "N"  exhibit  rather  remarkable  indi- 
vidual differences. 

In  both  series  of  memory  tests,  four  different  classes  of  errors  ap- 
peared. First,  the  substitution  of  one  digit  for  another;  second,  the 
omission  of  a  digit;  third,  a  digit  inserted;  fourth,  digits  placed  in 
their  reversed  order.  Any  method  of  valuation  of  errors  yet  devised 
seems  quite  arbitrary ;  therefore,  in  estimating  the  number  of  errors 
in  any  series  of  experiments  as  recorded  in  either  Table  X  or  Table  XII, 
the  writer  makes  no  discrimination  as  to  the  character  of  the  error. 
In  other  words,  each  error  made,  of  whatever  character,  counts  one. 
The  number  in  the  table  thus  shows  the  total  number  of  errors  in 
learning  the  different  series. 

It  may  be  said  that  the  results  of  the  tests  in  auditory  memory,  as 
shown  in  Table  XII,  are  the  reverse  of  what  was  expected,  after  having 
found  that  the  vertical  position  is  slightly  favorable  to  discrimination 
of  pitch.  However,  Table  XII  shows  that  the  horizontal  position  is 
favorable  for  auditory  memory,  as  it  is  also  for  visual  memory.  The 
average  number  of  errors  per  individual  in  the  horizontal  position  is 
227,  with  a  M.V.  of  64.  In  the  vertical  position,  the  average  number 
of  errors  per  individual  is  250,  with  a  M.V.  of  64.  The  average  number 
of  trials  given  each  individual  to  learn  the  series  in  the  horizontal 
position  is  6.3.  with  a  M.V.  of  1.3,  while  in  the  vertical  position  each 
individual  has  on  an  average  7.3  trials  to  learn  the  series,  with  a  M.V. 
of  1.4.  It,  therefore,  seems  evident  both  from  the  standpoint  of  the 
number  of  errors  made  by  each  subject,  and  from  the  rapidity  with 
which  the  associations  are  remembered,  that  the  horizontal  posture  is 
favorable  to  auditory  memory,  with  the  subjects  tested  in  this  series. 

The  validity  of  the  blood  pressure  and  heart-beat  records  is  amply 
shown  by  a  comparison  of  Tables  X  and  XII.  It  will  be  noticed  that 


46 


INFLUENCE  OF  BODILY  POSTURE 


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PULSE  RATE,  BLOOD  PRESSURE,  ETC.  47 

in  the  extended  series  of  experiments  each  subject  tested  shows  very 
little  variation.  This  is  due  to  the  fact  that  such  a  large  number  of 
records  were  taken  for  each  individual,  and  the  mean  actually  shows 
these  two  physiological  phenomena  for  each  individual  tested.  It  is 
impossible  to  determine  normal  heart-beat  or  blood  pressure  of  an 
individual  by  a  few  tests,  because  slight  external  influences,  which  the 
experimenter  may  not  be  able  to  control,  are  sure  to  make  consider- 
able variations  in  both,  making  it  necessary  to  obtain  a  large  number 
of  results  from  tests  under  varying  conditions. 

By  arranging  these  fifteen  subjects  into  two  series,  one  for  physical 
condition,  and  the  other  for  efficiency  in  auditory  memory,  the  correla- 
tion was  found  by  the  same  method  as  in  the  preceding  chapter,  with 
r  equal  to  68.2.  This  result  makes  it  quite  certain  that  for  the  subjects 
tested  in  visual  and  auditory  memory,  there  is  a  decided  correlation 
between  their  mental  efficiency  in  these  two  lines  and  their  physical 
condition,  based  upon  a  comparison  of  heart-beat  and  blood  pressure 
in  the  two  positions  of  the  body. 


CHAPTER  IX 

A  COMPARISON  OF  TAPPING  RAPIDITY  IN  THE  HORIZONTAL  AND  VERTICAL, 
POSITIONS  OP  THE  BODY 

It  was  said  in  the  preceding  chapter  that  the  adding  tests  were 
alternated  with  the  tapping  tests.  This  was  done  in  connection  with 
the  experiments  conducted  in  the  Columbia  Laboratory  only.  It 
was  thought  by  this  method  that  fatigue  for  both  sets  of  tests  was  some- 
what avoided.  The  tapping  tests  were  conducted  in  the  following 
manner:  A  small  brass  pencil  was  held  in  the  fingers  in  a  convenient 
position  for  tapping  upon  another  piece  of  sheet  brass  which  was 
clamped  to  the  Mosso  instrument,  in  such  a  position  that  when  the 
arm  was  straightened  out  along  the  balance,  the  tapper  came  directly 
over  the  piece  of  sheet  brass.  A  record  of  the  taps  was  kept  by  an 
electric  tabulator,  made  by  Stoelting,  of  Chicago,  and  the  subject 
was  timed  with  a  stop-watch  for  one  hundred  taps.  Of  course,  when 
the  subject  was  rotated  from  one  position  to  another,  the  hand  re- 
mained in  the  same  relative  position  to  the  balance  and  to  the  piece 
of  sheet  brass  upon  which  the  taps  were  made.  There  is,  of  necessity, 
a  slight  difference  in  the  physical  conditions,  for  in  the  horizontal 
position  the  weight  of  the  hand  has  to  be  lifted  in  making  every  tap, 
while  in  the  vertical  posture  the  hand  has  only  to  make  a  swinging 
movement  similar  to  that  of  a  pendulum.  We  would  naturally  ex- 
pect this  to  make  some  difference  in  the  rapidity  with  which  the  move- 
ments could  be  made. 

Reference  to  Table  XIII  will  show  the  comparative  rapidity  of  this 
reaction  in  the  two  positions  of  the  body.  All  but  two  of  the  subjects 
tested  did  better  in  the  vertical  posture,  and  one  of  these,  Miss  F.r 
does  practically  the  same  in  the  two  positions,  but  has  a  greater  M.V. 
in  the  horizontal.  However,  taking  into  consideration  the  regularity 
of  her  speed  in  the  vertical  position,  she  really  did  better  in  the  latter. 
A  comparison  of  the  means  in  the  two  positions  for  all  subjects  tested 
shows  that  the  vertical  posture  is  slightly  favorable,  there  being  an 
advantage  of  about  four  taps  per  hundred  for  this  position. 

It  is  worthy  of  note  in  connection  with  this  series  of  tests  that  the 
subjects  showed  great  individual  differences  in  the  manner  of  inner- 
vating the  necessary  muscles  for  producing  the  movement.  They 
were  asked  to  keep  the  body  perfectly  still  while  making  the  tapping 
movement  and  cautioned  against  the  use  of  more  muscles  in  the 
execution  than  absolutely  necessary.  Nevertheless,  in  at  least  eight 
of  the  subjects,  there  were  marked  movements  in  other  parts  of  the 
body,  particularly  in  the  opposite  arm  and  leg,  and  even  in  the  muscles 


TAPPING  RAPIDITY  49 

TABLE  XIII 

Comparison  of  taps  made  in  the  horizontal  and  vertical  positions  of  the  body. 
Number  recorded  by  an  electric  tabulator. 


Horizontal 

Vertical 

I                             I1 

Tim* 

Time 

Subject 

Number  of 
tests 

Number  of 
tests 

Com  parative 
per  cents 

Mean 

M.V. 

Mean         M.V. 

F. 

24                12.4 

-5 

24 

12.4 

-7 

100% 

M. 

2O 

12.7 

-4 

2O 

12.3 

.6 

97% 

P. 

30 

13.05 

.8 

30 

12.  I 

I  .  2 

93% 

W.H.S. 

24 

ix.  7 

•9 

24 

II.  O 

.8 

94% 

D. 

2O 

11.9 

20 

11.7 

-3 

98% 

F. 

24          i      14-3 

1.2 

24 

I3-1 

.9 

Miss  F. 

12 

16.6 

2.  I 

12 

16.7 

100.6% 

W 

24 

17.0 

1.8 

24 

15-2 

-7 

89% 

S. 

2O 

13-5 

•  9 

2O 

12.7 

.8 

94% 

c. 

24 

15-05 

24 

14.4 

-4 

95% 

Miss  T. 

12 

18.4 

-5 

12 

17.9 

.6 

97% 

H. 

18 

12.9 

•  4 

18 

12.2 

•  5 

94% 

Miss  B. 

20 

14.8 

.  2 

20 

14.4 

.6 

Miss  S. 

18 

14.2 

.2 

18 

14.4 

•  3 

101% 

M. 

M. 

M. 

M. 

M. 

14.2 

M.V. 

.8 
M.V. 

13-6 
M.V. 

M.V7. 

95-7% 
M.V. 

i-5 

•5 

i-59 

.2 

3-2% 

of  the  shoulder  and  neck,  to  such  an  extent  that  the  head  moved 
rapidly  from  side  to  side.  Even  if  the  movements  did  not  show  them- 
selves in  other  parts  of  the  body,  it  was  evident  that  practically  all 
the  leading  muscles  of  the  skeletal  system  were  violently  contracted. 
Most  of  the  subjects  stated  that  this  state  of  muscular  contraction 
aided  them  very  materially  in  the  rapidity  of  the  movements.  It  is 
to  be  noted,  however,  that  the  three  subjects  making  the  best  records 
in  the  whole  series  did  not  show  this  violent  muscular  tonicity  in  other 
parts  of  the  body,  neither  did  there  appear  much  irregularity  in  the 
breathing  or  other  bodily  functions.  Those  making  the  best  records 
seemed  to  have  the  power  to  inhibit  all  impulses  to  other  muscles 
save  those  needed  for  these  rapid  movements.  The  subject  W.  H.  S. 
who  ranks  first  in  the  series,  and  who  twice  during  the  tests  made 
one  hundred  taps  in  nine  seconds,  equaling  the  world's  record, 
so  far  as  the  writer  has  been  able  to  discover,  made  the  movements 
with  apparent  ease  and  without  any  muscular  changes  or  innervations 
in  other  parts  of  the  body.  These  tests  would  thus  seem  to  show  that 
as  in  accuracy  of  movement,  so  in  rapidity  of  movement,  the  best 
results  are  attained  by  inhibiting  all  impulses  to  the  musculature 
except  those  absolutely  necessary  to  the  movement  itself.  If  this 
theory  be  true,  we  would  expect  to  find  much  improvement  by  practice, 
which  does  actually  appear  from  the  tests  made  in  this  series.  With- 


50  INFLUENCE  OF  BODILY  POSTURE 

out  exception  every  subject  made  considerable  improvement  during 
the  extensive  series  taken,  and  those  improved  most  whose  innervation 
to  other  muscles  was  greatest  in  the  beginning.  Of  course  their 
attention  was  constantly  called  to  the  unnecessary  movements  they 
made,  and  gradually  they  tended  to  disappear  and  greater  speed  was 
acquired.  Rapid  movements  thus  appeared  to  conform  to  the  law 
of  all  highly  specialized  movements.  The  athlete  who  wins  is  he  who 
knows  the  form  of  the  movement  to  be  made  and  is  able  to  inhibit  all 
unnecessary  movements.  The  nervous  energy  set  free  in  the  per- 
ipheral centers  thus  passes  directly  into  the  motor  centers  concerned  in 
the  sending  on  of  the  impulse  to  the  proper  muscles,  and  there  is  no 
waste.  The  nervous  energy1  being  confined  within  narrower  limits 
has  greater  facility  in  passing  the  synapses,  thus  making  the  movement 
more  quickly.  The  secret  of  being  able  to  make  rapid  movements  is 
thus  the  ability  to  control  the  nervous  energy  set  free  in  the  sensory 
-centers  into  the  precise  motor  centers  needed  to  make  the  movement. 

There  are  some  reactions,  such  as  holding  the  breath  and  violent 
facial  contortions,  which  were  very  noticeable  in  some  of  the  subjects 
who  did  poorest  in  these  tests.  One  subject  portrayed  such  violent 
muscular  contractions,  and  inhibited  breathing  to  such  an  extent 
during  the  whole  experiment  that  after  each  test  he  seemed  almost 
exhausted,  and  a  considerable  space  of  time  had  to  be  taken  for  re- 
cuperation, before  the  accompanying  tests  already  mentioned  could 
be  continued.  Such  subjects  always  do  poorly  in  these  tests.  No 
such  widely  distributed  muscular  effort  was  evident  in  the  subjects 
who  made  good  records.  On  the  contrary,  the  vibratory  movements 
of  the  greatest  rapidity  were  always  very  short,  and  unaccompanied 
by  any  motor  effects  in  any  other  part  of  the  body. 

1  McDougall,  Physiological  Psychology,  p.  32. 


CHAPTER  X 

A  COMPARISON  OF  FATIGUE  IN  THE  HORIZONTAL  AND  VERTICAL  POSITIONS 
OF  THE  BODY,  BY  THE  USE  OF  THE  FINGER  DYNAMOMETER 

The  method  of  taking  this  rather  tedious  series  of  tests  was  similar 
in  character  to  all  of  the  previous  series,  that  is,  the  subject  was 
placed  upon  the  Mosso  instrument  in  the  horizontal  position,  and  made 
to  press  the  finger  dynamometer  (the  Cattell  instrument)  fifty  times, 
from  the  record  of  which,  the  fatigue  curve  could  be  calculated.  Then 
after  sufficient  tune  had  elapsed  to  allow  the  fatigue  to  pass  away, 
the  test  was  repeated  in  the  vertical  posture.  For  the  greater  number 
of  the  subjects,  only  one  test  could  be  taken  per  day,  though  some  were 
able  to  take  one  in  the  forenoon,  and  one  in  the  afternoon,  allowing  as 
much  as  three  or  four  hours  to  intervene.  In  every  case,  there  was 
positive  assurance  that  the  effects  of  the  previous  test  had  passed 
away  before  the  next  was  taken.  In  some  cases  several  days  elapsed 
between  the  tests  in  the  two  positions. 

In  making  the  tests,  the  instrument  was  held  in  precisely  the  same 
relative  position  to  the  body,  whether  in  the  horizontal  or  vertical 
posture.  The  arm  and  wrist  were  made  to  rest  upon  the  Mosso  instru- 
ment at  the  side  of  the  body,  in  a  convenient  position  for  operating  the 
instrument,  which  was  held  between  the  thumb  and  forefinger  of  the 
right  hand.  At  a  given  signal,  the  subject  was  asked  to  press  the 
dynamometer  as  hard  as  he  could,  once  per  second  for  fifty  seconds. 
Subjects  were  cautioned  to  inhibit  all  other  movements  as  much  as 
possible,  and  to  exert  themselves  in  doing  their  best  at  each  successive 
effort. 

In  estimating  the  relative  ability  of  subjects  to  press  the  dynamom- 
eter, the  method  adopted  by  Wissler1  has  been  used  throughout.  Each 
subject  was  tested  at  least  ten  times  in  each  position,  and  the  figure  in 
the  "fatigue"  column  represents  the  mean  for  all  these  tests.  Of 
course,  the  fatigue  will  be  shown  by  the  degree  of  approximation  to  the 
initial  effort.  It  is  very  true  that  some  subjects  do  not  know  when 
they  have  done  their  best,  and  the  initial  effort  is  not  so  good  as  some 
of  the  later  ones.  Then  it  may  be  that  some  subjects  cannot  do  their 
best  until  they  are  "warmed  up."  However,  the  writer  believes  that 
in  the  extended  series,  the  results  of  which  are  given  in  Table  XIV, 
the  inadequacy  of  the  initial  efforts  makes  no  difference  in  the  validity 
of  the  comparative  results  herein  tabulated.  The  effort  is  only  to 
determine  differences,  if  any  occur,  in  the  horizontal  and  vertical 

1  Wissler,  The  Correlation  of  Mental  and  Physical  Tests,  p.  38. 


INFLUENCE  OF  BODILY  POSTURE 


TABLE  XIV 

A  comparison  of  fatigue  by  the  use  of  the  finger  dynamometer  in  the  horizontal 
and  vertical  positions  of  the  body. 


Horizontal 

Vertical 

Subject 

Number 
of  tests 

Fatigue 

M.V. 

Number 
of  tests 

Fatigue 

M.V. 

Comparative  per 
cents 

L. 

G. 

IO 
12 

70-3 
85.2 

5-8 

7-4 

10 
12 

73-5 
86.8 

6.1 
5-3 

104% 
102% 

T. 

IO 

91.4 

8.4 

IO 

90.2 

8.7 

98% 

M. 

12 

72.1 

5-7 

12 

78.6 

6-4 

109% 

M.' 

15 

65.4 

3-8 

15 

69  5 

4-7 

1  06% 

A. 

12 

81.1 

7-i 

12 

88.3 

8-4 

109% 

S. 

10 

85.2 

6-3 

IO 

90.2 

5-4 

106% 

w. 

10 

74-8 

4-7 

IO 

80.6 

5-3 

108% 

T' 

12 

81.7 

3-2 

12 

84.6 

4-6 

103% 

G' 

10 

74-3 

5-6 

10 

•  78.2 

6.1 

105% 

I/ 

IO 

85-5 

7.2 

IO 

90.3 

6.8 

1  06% 

A' 

12 

64.4 

5-2 

12 

70.6 

3-8 

108% 

B. 

IO 

87.7 

4-9 

IO 

90.6 

5-6 

103% 

D. 

IO 

84.1 

3-9 

IO 

88.6 

2.9 

105% 

M. 

M. 

M. 

M. 

M. 

78.8 
M.V. 

5-5 
M.V. 

82.8 
M.V. 

M5V?. 

105% 
M.V. 

7-3 

I  .  2 

6.6 

I  .  I 

2-2% 

position  of  the  body.  For  example,  subject  "L"  has  a  fatigue  record 
in  the  horizontal  position  of  70.3,  and  in  the  vertical  of  73.5.  These 
figures  are  obtained  as  follows:  For  each  test  made,  the  total  reading 
was  divided  by  five  times  the  sum  of  the  first  ten  pressures.  These 
results  were  added  together  and  divided  by  the  total  number  of  tests 
made,  as  indicated  in  column  two  of  the  table. 

The  results  of  the  tests  are  quite  conclusive  so  far  as  the  subjects 
tested  are  concerned.  Much  greater  fatigue  is  shown  in  the  horizontal 
posture  than  in  the  vertical.  The  mean  for  the  horizontal  is  78.8, 
and  for  the  vertical  is  82.8.  The  comparative  per  cents,  show  that  the 
quantity  of  fatigue  shown  in  the  horizontal  position  is  approximately 
105  per  cent,  of  that  shown  in  the  vertical  position. 

Theoretically,  this  would  be  expected.  The  vertical  posture  is 
normal  for  muscular  effort.  When  the  weight  is  thrown  upon  the  feet 
and  the  blood  pressure  is  increased  throughout  the  body,  the  tonicity 
of  the  whole  musculature  is  more  easily  sustained,  and  muscular  co- 
ordination facilitated.  Mere  force  of  habit  and  association  would  aid 
the  muscular  effort  in  the  vertical  posture,  for  one  rarely  engages  in 
any  violent  exercise  in  the  horizontal  posture.  The  latter  posture  is 
used  for  repose  habitually,  and  is  not  surprising  that  muscles  are  more 
readily  fatigued  under  great  activity  when  in  a  position  in  which  they 
are  normally  relaxed. 


CHAPTER  XI 

A  COMPARISON  OP  THE  STRENGTH  OF  GRIP,  BY   THE   USE   OF   THE    HAND 

DYNAMOMETER,  IN  THE  HORIZONTAL  AND  VERTICAL    POSITIONS 

OF   THE   BODY 

It  will  be  noticed  that  the  subjects  employed  in  this  series  of 
tests  are  the  same  as  those  used  in  the  visual  memory  tests.  In  fact, 
all  subjects  tested  in  visual  memory  were  at  the  same  time  tested  in 
strength  of  grip  by  the  use  of  the  hand  dynamometer.  The  tests 
were  so  alternated  with  those  of  blood  pressure,  and  heart-beat,  and 
visual  memory  as  to  allow  all  the  effects  of  fatigue  from  a  single  effort 
to  pass  away  before  the  second  effort  was  made.  The  general  plan 
employed  was  to  place  the  subject  upon  the  Mosso  instrument  in  the 
horizontal  position,  and  after  testing  the  heart-beat  and  blood  pressure, 
to  allow  the  subject  to  grip  the  dynamometer  as  strongly  as  he  could, 
after  which  the  visual  memory  tests  were  taken.  By  the  time  these 
were  finished  in  the  horizontal  position,  which  usually  occupied  eight 
or  ten  minutes,  and  the  subject  was  elevated  to  the  vertical  position, 
all  signs  of  fatigue  from  the  previous  test  had  passed  away  and  the 
second  test  could  be  taken.  This  method  continued  in  as  many  series 
of  tests  as  were  taken  for  visual  memory,  and  in  most  instances  it  will 
be  found  that  the  number  of  tests  taken  correspond  exactly  with  the 
number  taken  for  visual  memory.  In  every  case  the  subject  was  asked 
to  take  the  dynamometer  in  his  right  hand,  allowing  the  arm  to  rest 
on  the  Mosso  instrument,  and  without  moving  other  parts  of  the  body, 
to  grip  it  as  strongly  as  possible.  Since  the  hand  and  arm  are  in  the 
same  relative  position  to  the  body  whether  standing  or  lying  down, 
theoretically,  from  the  mere  standpoint  of  position,  no  difference  in  the 
strength  of  the  grip  would  be  expected.  However,  the  table  indicates 
that  subjects  have  a  stronger  grip  in  the  vertical  than  in  the  horizontal 
position.  The  explanation  is  seemingly  to  be  found  in  the  fact  that 
in  the  vertical  posture,  the  blood  pressure  is  generally  higher  and  the 
muscular  tonicity  more  easily  maintained. 

By  referring  to  Table  XV  (next  page),  it  is  seen  that 
only  two  subjects  do  better  hi  the  horizontal  than  in  the  vertical 
position.  There  are  as  many  as  thirteen  who  do  practically  the  same 
in  the  two  positions,  there  being  only  a  slight  advantage  in  favor  of  the 
vertical.  But  there  are  ten  subjects  who  do  very  much  better  in  the 
vertical,  bring  the  comparative  per  cent,  up  to  105  in  favor  of  the 
vertical  position.  This  is  rather  a  decided  tendency.  Indeed  the  two 
subjects  who  did  poorer  in  the  vertical  are  counted  among  those  who 
did  practically  the  same  in  the  two  positions,  and  it  is  possible  that 


54 


INFLUENCE  OF  BODILY  POSTURE 


if  ten  more  experiments  had  been  performed  on  these  subjects  an 
equal  tendency  might  be  found  in  the  opposite  direction.  The  mean 
strength  of  all  subjects  tested  in  the  horizontal  position  is  57.2  with 
a  mean  variation  of  2.6,  while  in  the  vertical  position  of  the  body,  the 
mean  strength  of  all  the  subjects  is  60.3  with  a  mean  variation  of  6.2. 

TABLE  XV 

A  comparison  of  grip  in  the  horizontal  and  vertical  positions  of  the  body  by 
the  use  of  the  hand  dynamometer. 


Horizontal 

Vertical 

Subject 

Number 
of  tests 

M. 

M.V. 

Number 
of  tests 

M. 

M.V. 

Comparative  per 
cents 

H. 

10 

71-3 

2-3 

10 

78.0 

4-2 

109% 

B. 

12 

36.2 

i-5 

12 

42.0 

2-3 

117% 

S. 

IO 

32-6 

2-3 

IO 

32.2 

i-5 

98% 

S.' 

IO 

53-2 

2.  I 

IO 

54-8 

2.7 

103% 

M. 

12 

52-3 

2.6 

12 

56.2 

3i 

107% 

R. 

C. 

12 
15 

68.4 
61. 

3-5 
2-3 

12 
15 

75-3 
7i-3 

2.8 

3-5 

110% 

1  1  8% 

a* 

IO 

69. 

3-5 

10 

70.2 

2.1 

102% 

F. 

12 

56- 

2.7 

12 

57-2 

I  .2 

102% 

P.' 

IO 

76. 

2. 

10 

80.5 

3-2 

106% 

G. 

12 

56. 

3- 

12 

60.2 

2-5 

107% 

L. 

15 

60. 

3- 

15 

65-1 

2.  I 

108% 

A. 

2O 

35- 

2. 

2O 

37-3 

1.8 

106% 

C.' 

10 

62. 

3- 

IO 

64.4 

2.8 

103% 

D. 

IO 

33- 

3- 

IO 

40.4 

3-7 

121% 

Js> 

12 
IO 

63- 

37- 

i-4 

2.6 

12 
IO 

67.2 
38.2 

4-3 
2-7 

105% 
103% 

N. 

15 

48. 

3-4 

15 

49.1 

1.8 

102% 

H.' 

IO 

76. 

2-3 

IO 

78.2 

i-3 

IO2% 

H.* 

12 

68. 

3-i 

12 

69  5 

2.6 

102% 

M.' 

15 

59- 

2-5 

15 

63.7 

2-3 

108% 

K. 

IO 

3°. 

i-5 

IO 

29.6 

2.6 

97% 

A.' 

12 

65- 

2-3 

12 

67.2 

3-1 

102% 

L.' 

IO 

68. 

i-4 

10 

71.2 

3-2 

104% 

I. 

12 

61. 

3-i 

12 

65.8 

i-4 

107% 

S."" 

IO 

70-3 

2.6 

IO 

7»-4 

2.7 

101% 

P. 

10 

70.4 

4-i 

IO 

72.4 

3-4 

102% 

M. 

M. 

M. 

M. 

M. 

57-2 

2.6 

60.3 

2.6 

105% 

M.V. 

M.V. 

M.V. 

M.V. 

M.V. 

ii.  6 

-5 

12.3 

-7 

4-i% 

It  seems  to  the  writer  that  this  series  of  tests  gives  conclusive 
evidence  that  when  the  body  is  erect  there  is  greater  strength  of  the 
grip  than  when  the  body  is  in  a  reclining  posture.  This  table,  probably 
more  than  any  other  series  of  tests  presented,  shows  clearly  special 
adaptation  for  strength  in  the  vertical  position.  The  results  of  this 
series  show  too  that  the  strength  tests  given  in  the  gymnasiums  are 
valid  only  when  all  subjects  are  required  to  maintain  the  body  in 
precisely  the  same  position  for  each  of  the  tests. 


CHAPTER  XII 

SOME  ADDITIONAL  DATA  UPON  THE  PRECEDING  RESULTS 

In  order  to  verify  the  results  of  the  tests  recorded  in  the  preceding 
chapters,  it  was  thought  advisable  to  select  four  subjects  who  had  not 
been  employed  in  the  previous  experiments  and  take  them  through 
all  the  tests  in  precisely  the  same  manner  in  which  the  original  tests 
were  made.  It  will  be  remembered  that  all  the  subjects  used  here- 
tofore were  those  selected  from  the  various  departments  of  the  uni- 
versity who  were  willing  to  give  a  little  tune  to  the  investigation,  and 
in  consequence  of  this  fact,  the  list  of  subjects  is  a  very  naive  and 
irregular  one.  There  was  great  difficulty  in  securing  the  same  subjects 
for  two  consecutive  series.  The  results  attained  are  thus  from  groups 
of  individuals  varying  materially  from  each  other,  both  in  size  and 
psychological  training.  For  this  reason,  it  might  reasonably  be  expected 
that  while  there  is  a  certain  validity  in  the  result  for  this  particular 
group,  another  group  of  individuals,  having  more  training  and  being 
selected  with  special  reference  to  this  test,  might  show  entirely  different 
results.  The  writer,  therefore,  selected  four  men  who  were  willing 
to  serve  as  subjects  in  the  following  series:  discrimination  of  pitch, 
tactile  discrimination,  visual  memory,  auditory  memory,  adding,  tap- 
ping test,  fatigue  test,  and  grip.  These  subjects  were  not  exactly 
naive,  but  had  had  a  little  experience  in  the  methods  of  the  psychological 
laboratory.  Two  were  students  in  Teachers'  College,  Columbia  Uni- 
versity, and  one  a  teacher  in  the  New  York  City  Schools.  All  had 
taken  courses  in  psychology  and  were  interested  in  the  subject  in  the 
experimental  field,  but  had  done  very  little  practical  work.  The 
results  following  are  therefore  results  of  practically  naive  subjects, 
but  seem  to  the  writer  to  have  greater  weight,  because  the  same  group 
of  individuals  is  used  for  each  series. 

It  does  not  seem  necessary  to  explain  the  succeeding  tables,  for  all 
the  tests  were  taken  in  precisely  the  same  manner  as  those  described 
in  the  previous  chapters.  The  same  apparatus  was  used  in  every 
instance,  and  the  same  method  of  tabulating  and  recording.  A  com- 
parison of  the  corresponding  series  of  experiments  shows  that  in  general 
the  results  of  the  former  tests  are  verified  by  those  recorded  in  this 
chapter.  It  is  true  there  is  some  little  variation,  but  on  the  whole 
the  results  are  the  same  in  the  various  series.  In  order  that  the  com- 
parative results  may  be  quickly  and  easily  seen,  the  tables  in  this 
chapter  will  contain  also  the  results  found  in  the  tables  in  the  previous 
chapters. 


56 


INFLUENCE  OF  BODILY  POSTURE 


jN 

?   65   65    65 
H     2    * 

-^ 

H 

s 

+  |  +    +    + 

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00 

t^ 

+ 

M 

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p 

NO 

+         + 

•s 

- 

+         + 

1 

1 

•* 

t  i       ti 

> 

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+     +     +     + 

- 

+     +     +     + 

rO        ^        rO        •<*• 

~ 

+I+I+++I 
wNfOl-lMwlON 

H 
•I 

V 

1 

> 
2 

M      M       M      eq 

lO         TJ-         lO         «O 

2  ^'K  Tt' 
^S 

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j| 

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fO       vo         •*        ON 

03        -.'       vd        r^. 

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SvbJ-vc; 
^  s 

q 

.  ^s.'  "*" 
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Number 
of  ex- 

peri- 

inents 

O        O        •*       oo 

FORWAF 

0 

+   +    1 

fc     Tj-     i 

i 

0\ 

i 

00 

E 

r- 

P 

• 

NO 

5 

1 

•- 

>0 

+     + 

i 

I 

•* 

i 

ro 

+          +    + 

3 

n 

+    +  1  +    + 

10      M  a  «•)      M 

! 

M 

I++I+I+I 

§ 

3 

w           t^          PI           W 

+    n    »>     i* 

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S*S- 

.->« 

s^s  - 

H 

s 

+        PO                   VO 

\d      <>      "^      od 

00  >  °* 

s  ?s  ^ 

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a**"0 

lr?t 
r°*= 

O        O        ••*•      oo 

P>    H          M          M 

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SOME  ADDITIONAL  DATA 


57 


DISCRIMINATION   OP   PITCH 


Horizontal 

Vertical 

Subject 

A 

Number  of 
experi- 
ments 

Per  cent 
right 

P.E. 

A 

Number  of 
experi- 
ments 

Per  cent 
right 

P.E. 

Comparative 
per  cents 

M. 

2 

150 

62 

4-4 

2 

150 

68 

2.8 

64% 

G. 

3 

100 

85 

i-9 

3 

IOO 

87 

1.8 

94% 

S. 

2 

IOO 

91 

i  .0 

2 

IOO 

93 

•9 

90% 

A. 

3 

100 

80 

2-4 

3 

IOO 

82 

2.  2 

9i% 

M. 

M. 

M. 

2.4 
M.V. 

i-9 

M.V. 

85% 
M.V. 

•9 

•  5 

10% 

RESULTS   BROUGHT   FORWARD   FROM   TABLE   III 


M. 

M. 

M. 

3-6 

2.  2 

78% 

M.V. 

M.V. 

M  V. 

i-9 

.8 

21% 

TACTILE   DISCRIMINATION 


Horizontal 

Vertical 

Subject 

A 

Number 
of  experi- 
ments 

Per  cent 
right 

P.E. 

A 

Number 
of  experi- 
ments 

Per  cent 
right 

P.E. 

Comparative 
per  cents 

M. 

I 

IOO 

85 

.6 

I 

IOO 

76 

•9 

150% 

G. 

.  i 

IOO 

92 

•  4 

I 

IOO 

90 

•  5 

125% 

S. 

I 

IOO 

85 

.6 

I 

IOO 

86 

.6 

100% 

A. 

I 

IOO 

82 

•  7 

I 

IOO 

80 

.8 

"4% 

M. 

M. 

M. 

•57 

•  7 

122% 

M.V. 

M.V. 

M.V 

.09 

•15 

15% 

RESULTS   BROUGHT   FORWARD   FROM   TABLE   VI 


M. 

M. 

M. 

1.16 

1-7 

146% 

M.V. 

M.V. 

M.V: 

•24 

-59 

36% 

58 


INFLUENCE  OF  BODILY  POSTURE 


VISUAL   MEMORY 


Horizontal 

Vertical 

Comparative  per 

Subject 

Number 

Mean 
trials 

Errors 

Number 

Mean 
trials 

Errors 

cents 

Means 

Errors 

M. 

14 

8.7 

362 

H 

8-9 

521 

102% 

144% 

G. 

12 

4-6 

174 

12 

5-2 

223 

"3% 

128% 

S. 

15 

5-4 

211 

5 

5-3 

263 

98% 

124% 

A. 

12 

4-3 

185 

12 

4-9 

243 

"4% 

I3i% 

M. 

M. 

M. 

M. 

M. 

M. 

M5V7. 

®. 

6.0 
M.V. 

& 

106% 
M.V. 

& 

1.7 

64 

i-3 

104 

6% 

6% 

RESULTS   BROUGHT   FORWARD   FROM   TABLE   X 


M. 

M. 

M. 

M. 

iv. 

M9V9 

& 

236 
M.V. 

1*5 

66 

i-3 

58- 

AUDITORY   MEMORY 


Horizontal 

Vertical 

Comparative  per 

Subject 

Number 

Mean 

Errors 

Number 

Mean 

Errors 

cents 

Means 

Errors 

M. 

IO 

4-2 

126 

10 

4-6 

285 

108% 

226% 

G. 

12 

3-6 

172 

12 

3-9 

196 

1  08% 

"4% 

S 

14 

5-9 

295 

14 

6-4 

372 

1  08% 

127% 

A. 

12 

8-7 

431 

12 

8.6 

450 

98% 

104% 

M. 

M. 

M. 

M. 

M. 

M. 

5-6 
M.V. 

256 
M.V. 

5-8 
M.V. 

325 
M.V. 

105% 
M.V. 

142% 
M.V. 

i-7 

107 

1.6 

85 

4% 

4i% 

RESULTS   BROUGHT   FORWARD    FROM   TABLE    XII 


M 

M. 

M. 

M. 

6-3 
M.V. 

227 
M.V. 

i* 

M5V° 

i-3 

64 

»-4 

64 

SOME  ADDITIONAL  DATA 


TAPPING  TEST 


Horizontal 

Vertical 

Time 

Time 

Subject 

Number 

Number 
of  tests 

Comparative 

M. 

M.V. 

M. 

M.V. 

M. 

30 

11.4 

.6 

30 

II.  2 

•3 

98% 

G. 

24 

12.8 

•  7 

24 

12.  I 

•  4 

94% 

S. 

18 

14-7 

.6 

18 

13-8 

•  5 

94% 

A. 

26 

I5-I 

.8 

26 

14.4 

•4 

97% 

M. 

M. 

M. 

M. 

M. 

at 

.67 

M.V. 

12.8 

M.V. 

•  4 
M.V. 

95% 
M.V. 

1.4 

.07 

1.2 

•05 

2  +  % 

RESULTS   BROUGHT   FORWARD   FROM   TABLE   XIII 


M. 

M. 

M. 

M. 

M. 

14.2 

.8 

13-6 

•  7 

95-  7% 

M.V. 

M.V. 

M.V. 

M.V. 

M.V. 

1-5 

•  5 

i-59 

.2 

3-2% 

Horizontal 

Vertical 

Subject 

No.of 
tests 

Fatigue 

M.V. 

Fatigue 

No.of 
tests 

M.V. 

Comparative 
per  cents 

M. 

12 

92.7 

3-4 

99-5 

12 

3-2 

107% 

G. 

IS 

79-2 

8.6 

87.6 

15 

9-2 

110% 

S. 

12 

84-3 

4-7 

89.5 

12 

3-8 

1  06% 

A. 

2O 

74-2 

ii.  6 

80.2 

2O 

8-7 

108% 

M. 

M. 

M. 

M. 

M. 

M. 

82.6 

7.07 

89.2 

6.2 

107-7% 

M.V. 

M.V. 

M.V. 

M.V. 

M.V. 

5-9 

3.02 

5-3 

2.7 

1.2% 

RESULTS   BROUGHT   FORWARD   FROM    TABLE   XIV 


M. 

M. 

M. 

M. 

M. 

78.8 
M.V. 

5-5 
M.V. 

82.8 
M.V. 

5-7 
M.V. 

105% 
M.V. 

7-3 

1.2 

6.6 

i  .  i 

2.2% 

INFLUENCE  OF  BODILY  POSTURE 


Horizontal 

Vertical 

Subject 

Number 
of  tests 

M. 

M.V. 

Number 
of  tests 

M. 

M.V. 

Comparative 
per  cent* 

M. 

10 

64.4 

5-2 

10 

68.3 

4-i 

106% 

G. 

12 

49  .2 

4.6 

12 

52-3 

5   i 

107% 

S. 

15 

54-6 

5-8 

15 

53-2 

7.6 

98% 

A. 

12 

61.2 

4-7 

12 

65-3 

94 

1  06% 

M. 

M. 

M. 

M. 

M. 

57-3 
M.V. 

50 
M.V. 

59-7 
M.V. 

6-5 
M.V. 

104% 
M.V. 

5-4 

•  4 

7.0 

19 

3% 

RESULTS   BROUGHT   FORWARD    FROM   TABLE   XV 


M. 

M. 

M. 

M. 

M 

57-2 

2.6 

60.3 

2.6 

105% 

M.V. 

M.V. 

M.V. 

M.V. 

MV. 

n.  6 

•5 

12.3 

•7 

4-i% 

Summing  up  the  results  of  all  the  tests  made  in  the  various  series, 
there  is  no  doubt  that  for  the  subjects  tested,  pitch  is  discriminated 
better  in  the  vertical  than  in  the  horizontal  position ;  tactile  discrimina- 
tion is  slightly  more  acute  in  the  horizontal  than  in  the  vertical ;  visual 
memory  is  both  more  rapid  and  subject  to  fewer  errors  in  the  hori- 
zontal than  in  the  vertical  position ;  auditory  memory  shows  the  same 
result  as  the  visual  memory;  adding  can  be  done  more  rapidly  and 
with  greater  precision  in  the  horizontal  posture ;  subjects  show  greater 
signs  of  fatigue  in  the  horizontal  than  in  the  vertical  posture;  a  greater 
number  of  taps  per  minute  can  be  made  in  the  vertical  than  in  the 
horizontal  position;  and  the  vertical  position  is  favorable  to  the 
strength  of  grip. 


ACKNOWLEDGMENTS 

The  greater  part  of  the  experimental  work  of  this  investigation  was 
carried  on  in  the  Psychological  Laboratory  of  Columbia  University. 
The  writer  is  indebted  to  Professor  J.  McKeen  Cattell  and  to  Professor 
R.  S.  Woodworth  for  many  courtesies,  and  valuable  suggestions  in  the 
conducting  of  the  numerous  series  of  tests.  He  also  wishes  to  express 
his  thanks  and  obligations  to  Professor  E.  L.  Thorndike,  of  Teachers' 
College,  for  valuable  suggestions  upon  some  parts  of  the  statistical 
work  involved  in  the  dissertation.  He  is  indebted  to  all  who  served 
as  subjects  throughout  the  long  series  of  tests,  to  the  assistants  in  the 
Psychological  Laboratory,  Dr.  Vivian  A.  C.  Henmon,  Mr.  Stevenson 
Smith,  and  Mr.  Hamilton,  and  to  the  fellow  in  psychology,  Dr.  F. 
Lyman  Wells,  and  all  special  students  in  psychology  who  gave  much 
time  for  the  carrying  on  of  the  work;  also  to  Mr.  W.  H.  Smith,  the 
mechanician  in  the  Laboratory.  These  subjects  have  records  appearing 
in  many  of  the  tables  throughout  the  investigation,  and  the  writer  feels 
under  the  deepest  obligations  to  them.  I  am  also  indebted  to  Miss  Lila 
London,  Professor  of  Mathematics  in  the  State  Female  Normal  School, 
Farmville,  Va.,  and  to  Dr.  J.  F.  Messenger,  Professor  of  Psychology 
and  Education,  for  valuable  suggestions  and  corrections  in  the  manu- 
script, and  reading  of  proof. 


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